#identifying partitions and checking if they are unmounted
> lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sdc      8:32   1   1.9G  0 disk
|-sdc1   8:33   1     1G  0 part
`-sdc2   8:34   1 910.5M  0 part

#identifying partition type, sector size, alignment, start and end blocks
> gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.5

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): p
Disk /dev/sdc: 3963904 sectors, 1.9 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D276E14A-5EB2-42FB-89DF-A742B6199BC3
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 3963870
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         2099199   1024.0 MiB  8300  Linux filesystem
   2         2099200         3963870   910.5 MiB   8300  Linux filesystem

Command (? for help): q

#resizing /dev/sdc1 to 100M
> ntfsresize -s 100M /dev/sdc1
ntfsresize v2012.1.15AR.5 (libntfs-3g)
Failed to set locale, using default 'C'.
Device name        : /dev/sdc1
NTFS volume version: 3.1
Cluster size       : 4096 bytes
Current volume size: 1073738240 bytes (1074 MB)
Current device size: 1073741824 bytes (1074 MB)
New volume size    : 99996160 bytes (100 MB)
Checking filesystem consistency ...
100.00 percent completed
Accounting clusters ...
Space in use       : 6 MB (0.5%)
Collecting resizing constraints ...
Needed relocations : 1412 (6 MB)
WARNING: Every sanity check passed and only the dangerous operations left.
Make sure that important data has been backed up! Power outage or computer
crash may result major data loss!
Are you sure you want to proceed (y/[n])? y
Schedule chkdsk for NTFS consistency check at Windows boot time ...
Resetting $LogFile ... (this might take a while)
Relocating needed data ...
100.00 percent completed
Updating $BadClust file ...
Updating $Bitmap file ...
Updating Boot record ...
Syncing device ...
Successfully resized NTFS on device '/dev/sdc1'.
You can go on to shrink the device for example with Linux fdisk.
IMPORTANT: When recreating the partition, make sure that you
  1)  create it at the same disk sector (use sector as the unit!)
  2)  create it with the same partition type (usually 7, HPFS/NTFS)
  3)  do not make it smaller than the new NTFS filesystem size
  4)  set the bootable flag for the partition if it existed before
Otherwise you won't be able to access NTFS or can't boot from the disk!
If you make a mistake and don't have a partition table backup then you
can recover the partition table by TestDisk or Parted's rescue mode.

#calculating the new start of /dev/sdc2 in bytes (/dev/sdc1 start block)*(sector size)+(new size of /dev/sdc1 in bytes)
> echo $((2048*512+100*1024*1024))
105906176

#calculating the new start of /dev/sdc2 in sectors (size in bytes)/(sector size)
> echo $((105906176/512))
206848

#checking alignment (new start in sectors)%(alignment) 0=aligned, >0=not aligned
> echo $((206848%2048))
0

#moving /dev/sdc2 to the left bs=(sector size), seek=(new start in sectors)
dd if=/dev/sdc2 of=/dev/sdc bs=512 seek=206848
1864671+0 records in
1864671+0 records out
954711552 bytes (955 MB) copied, 80.6772 s, 11.8 MB/s

#resizing and moving partitions preserving GUIDs (start sector of /dev/sdc2 must match)
> gdisk /dev/sdc
GPT fdisk (gdisk) version 0.8.5

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help): i
Partition number (1-2): 1
Partition GUID code: 0FC63DAF-8483-4772-8E79-3D69D8477DE4 (Linux filesystem)
Partition unique GUID: 359B474B-0EE0-46B5-A105-A57C1D60E863
First sector: 2048 (at 1024.0 KiB)
Last sector: 2099199 (at 1.0 GiB)
Partition size: 2097152 sectors (1024.0 MiB)
Attribute flags: 0000000000000000
Partition name: 'Linux filesystem'

Command (? for help): i
Partition number (1-2): 2
Partition GUID code: 0FC63DAF-8483-4772-8E79-3D69D8477DE4 (Linux filesystem)
Partition unique GUID: 93FD4BBB-F574-40D2-AC20-4FC162FDDEA3
First sector: 2099200 (at 1.0 GiB)
Last sector: 3963870 (at 1.9 GiB)
Partition size: 1864671 sectors (910.5 MiB)
Attribute flags: 0000000000000000
Partition name: 'Linux filesystem'

Command (? for help): d
Partition number (1-2): 1

Command (? for help): d
Using 2

Command (? for help): n
Partition number (1-128, default 1): 1
First sector (34-3963870, default = 2048) or {+-}size{KMGTP}: 2048
Last sector (2048-3963870, default = 3963870) or {+-}size{KMGTP}: +100M
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'

Command (? for help): n
Partition number (2-128, default 2):
First sector (34-3963870, default = 206848) or {+-}size{KMGTP}: 206848
Last sector (206848-3963870, default = 3963870) or {+-}size{KMGTP}:
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'

Command (? for help): x

Expert command (? for help): c
Partition number (1-2): 1
Enter the partition's new unique GUID ('R' to randomize): 359B474B-0EE0-46B5-A105-A57C1D60E863
New GUID is 359B474B-0EE0-46B5-A105-A57C1D60E863

Expert command (? for help): c
Partition number (1-2): 2
Enter the partition's new unique GUID ('R' to randomize): 93FD4BBB-F574-40D2-AC20-4FC162FDDEA3
New GUID is 93FD4BBB-F574-40D2-AC20-4FC162FDDEA3

Expert command (? for help): p
Disk /dev/sdc: 3963904 sectors, 1.9 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): D276E14A-5EB2-42FB-89DF-A742B6199BC3
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 3963870
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          206847   100.0 MiB   8300  Linux filesystem
   2          206848         3963870   1.8 GiB     8300  Linux filesystem

Expert command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sdc.
The operation has completed successfully.

#resizing /dev/sdc2 filesystem
> resize2fs /dev/sdc2
resize2fs 1.42.5 (29-Jul-2012)
Resizing the filesystem on /dev/sdc2 to 469627 (4k) blocks.
The filesystem on /dev/sdc2 is now 469627 blocks long.