AmazonAWS Fix EC2 Disconnected SSH RDP NO ACCESS!

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Getting access to misconfigured AmazonAws Instance...
For my case it was the misconfigured Ubuntu /etc/ssh/sshd_config
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Video I used for help:
Troubleshooting an RDP Connection with the EC2 Rescue Tool for Windows
https://www.youtube.com/watch?v=WFsWQrm1qi0&ab_channel=EricintheCloud

EC2Rescue for EC2 Windows is a troubleshooting tool that you can run on your Amazon EC2 Windows Server instances. You can use the tool to troubleshoot OS-level issues and collect advanced logs and configuration files for further analysis.
PowerShell Command to Download the EC2 Rescue tool:
https://s3.amazonaws.com/ec2rescue/windows/EC2Rescue_latest.zip?x-download-source=docs

(Except I didn't use Windows Nor the Tool)
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Website I used for help:
How to access files of my First Ubuntu from my Second Ubuntu by adumbprogrammer:
https://askubuntu.com/questions/1367142/how-to-access-files-of-my-first-ubuntu-from-my-second-ubuntu
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#0) First try accessing AmazonAWS Cloud Shell... If to no avail...

#0.5) This requires 2 instances. Using parition access...
So what we will do for sake of clarity call EC0 the misconfigured Server
and we will call EC1 the newly setup server we will create later...

#1) Go to failed AmazonAWS Server in AWS Control Panel EC2 Instance...

#2) Click on Instance checkbox of Name:
In details tab below:
Copy to clipboard: instance-ID: i-###x###x##x#x##x# and paste somewhere for later
and also: "Subnet-ID": subnet-0xx###x#xx###xx## and paste somewhere for later

#3) Go to Instance State and "Stop Instance".

#) Wait for it in "Instance State" to say "Stopped", then click on storage tab below.
Click on hyperlinked blue Volume-ID of volume in "Block Devices" drop-down tab
	Volume-ID	Device-Name	Vol.size	Attachment-status
(vol-0xx##x##xx####x##   /dev/sda1	   8	 	    Attached

A new page will popup, with more details...
Click on hyperlinked vol-0xx##x##xx####x## again.
Click "Actions" drop-down-tab and select "Detach Volume"
Wait till it says "Volume State" is "available" rather than "in use"
For the sakes of being careful copy and paste the vol-0xx... ID for safe keeping
as to not mix them up with the new-server vol-0xx ID.

#4) Create a new (Ubuntu) "Launch an " Instance in EC2.
Name it whatever you want, we'll call it EC1.
Quick-Start tab > Ubuntu (Server 22.04 LTS (HVM), SSD, (FREE)(64-bit))
(I already had an ssh putty.ppk key pair, so i used it, otherwise create one...
and after creating the new server, download the ssh-key-pair, we'll need it for putty access later.

In Network settings, click on Subnet, where it says "No Preference" tab,
and click it, and paste the "Subnet-ID": subnet-0xx###x#xx###xx## from earlier from EC0.

Once you have selected the Subnet-ID for the same subnet as your EC0 for EC1...
Continue to scroll to bottom of page and select the button "Launch instance".

#5) You should now have 2 instances. Make sure both Instance States are "Stopped".
Once Stopped, copy instance-ID of EC1 for later...

checkbox <check> the EC1 Name of instance.
Click on "Storage" tab below by details.
As before, click "Volume-ID" of any "vol-0xx##x##xx####x##"

#6) Once in Volumes window, click the "x" to close selected volume to display all volumes.
Now there should be 2 volume-ids:
"vol-0xx##x##xx####x#0" //EC0
"vol-0xx##x##xx####x#1" //EC1

Since we detached EC0's "vol-0xx##x##xx####x#0" Volume-ID, we should be able to use it on EC1.
To do this, click on EC0's "vol-0xx##x##xx####x##".
Then click on "Actions" tab and "Attach Volume".
In the new popup window, for Instance, paste EC1's Instance-ID.
Leave Device name AS-IS. No need to change.
Volume should now be connected to the EC2 instance...
to verify this go to Server2 Instance Details, Storage, and it should be so.

Now click on "Connect" Tab in EC2>Instances>instance-id>Connect to instance and choose SSH client.

Open putty and connect with: ubuntu@ec2-#-###-###-###.us-east-2.compute.amazonaws.com with SSH-KEY putty.apk create/used earlier, when creating EC1 Instance.

#7 Once Connected to EC1 instance, with volume of EC0 on EC1 attached from the same subnet, we can run these commands in ssh (putty) terminal...

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In putty ssh of EC1:
lsblk (THIS WILL SHOW ALL AVAILABLE DRIVES)
NAME     MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0      7:0    0  24.9M  1 loop /snap/amazon-ssm-agent/7628
loop1      7:1    0  55.7M  1 loop /snap/core18/2812
loop2      7:2    0  63.5M  1 loop /snap/core20/2015
loop3      7:3    0 111.9M  1 loop /snap/lxd/24322
loop4      7:4    0  40.9M  1 loop /snap/snapd/20290
xvda     202:0    0     8G  0 disk
├─xvda1  202:1    0   7.9G  0 part /
├─xvda14 202:14   0     4M  0 part
└─xvda15 202:15   0   106M  0 part /boot/efi
xvdf     202:80   0     8G  0 disk
├─xvdf1  202:81   0   7.9G  0 part
├─xvdf14 202:94   0     4M  0 part
└─xvdf15 202:95   0   106M  0 part


sudo mount /dev/xvdf1 /mnt (MOUNT THE DRIVE WE WANT TO FIX)
sudo nano /mnt/etc/ssh/sshd_config (MODIFY FROM /MNT/ DIR THE FILES WE NEED TO FIX)
<modify contents to fix ssh permission problem>
<save>
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shutdown the server instance till it says "Stopped"
Detach Volume from EC1, using the same as before on EC0, but for EC1... (!!!) Make sure you detach the same volume as before! For EC0!.
Reattach (THE CORRECT) volume to EC0 (!!!!)Make sure that you add the right VOLUME!
ALSO!!! Make sure you choose Instance-ID of server1, and CHANGE "DEVICE NAME" TO: /dev/sda1 and NOT: xvdf !!!!

Relaunch EC0 (previously misconfigured instance).
Once Running, it should be accessible once again (via ssh in my case).

Note** My ipaddress changed for my server after fixing ssh and had to
recopy and paste from amazonAWS "Public IPv4 DNS":

ubuntu@ec2-#-###-###-###.us-east-2.compute.amazonaws.com
and in putty-tab, SSH/Auth/Credentials/Private Key File For Authentication: <putty.ppk>
Back in Session "Save" session with "Saved Sessions" id of your choosing.

Viola! Back to front, ready to go!
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