[root@<SERVERNAME> /etc/jellyfin $ systemctl stop jellyfin
[root@<SERVERNAME> /etc/jellyfin $ dpkg -l | grep jellyfin
ii  jellyfin                               10.9.8+ubu2204                          all          Jellyfin is the Free Software Media System.
rc  jellyfin-ffmpeg5                       5.1.4-3-jammy                           amd64        Tools for transcoding, streaming and playing of multimedia files
ii  jellyfin-ffmpeg6                       6.0.1-7-jammy                           amd64        Tools for transcoding, streaming and playing of multimedia files
ii  jellyfin-server                        10.9.8+ubu2204                          amd64        Jellyfin is the Free Software Media System.
ii  jellyfin-web                           10.9.8+ubu2204                          all          Jellyfin is the Free Software Media System.
[root@<SERVERNAME> /etc/jellyfin $ apt remove jellyfin-ffmpeg5
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package 'jellyfin-ffmpeg5' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
[root@<SERVERNAME> /etc/jellyfin $ 
[root@<SERVERNAME> /etc/jellyfin $ dpkg -P jellyfin-ffmpeg5
(Reading database ... 87655 files and directories currently installed.)
Purging configuration files for jellyfin-ffmpeg5 (5.1.4-3-jammy) ...

[root@<SERVERNAME> /etc/jellyfin $ dpkg -l | grep jellyfin
ii  jellyfin                               10.9.8+ubu2204                          all          Jellyfin is the Free Software Media System.
ii  jellyfin-ffmpeg6                       6.0.1-7-jammy                           amd64        Tools for transcoding, streaming and playing of multimedia files
ii  jellyfin-server                        10.9.8+ubu2204                          amd64        Jellyfin is the Free Software Media System.
ii  jellyfin-web                           10.9.8+ubu2204                          all          Jellyfin is the Free Software Media System.

[root@<SERVERNAME> /etc/jellyfin $ sudo apt reinstall jellyfin-ffmpeg6

sudo systemctl start jellyfin
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 45.3 MB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 https://fra1.mirror.jellyfin.org/files/ubuntu jammy/main amd64 jellyfin-ffmpeg6 amd64 6.0.1-7-jammy [45.3 MB]
Fetched 45.3 MB in 1s (38.9 MB/s)            
(Reading database ... 87655 files and directories currently installed.)
Preparing to unpack .../jellyfin-ffmpeg6_6.0.1-7-jammy_amd64.deb ...
Unpacking jellyfin-ffmpeg6 (6.0.1-7-jammy) over (6.0.1-7-jammy) ...
Setting up jellyfin-ffmpeg6 (6.0.1-7-jammy) ...
Processing triggers for libc-bin (2.35-0ubuntu3.8) ...
...
[root@<SERVERNAME> /etc/jellyfin $ service jellyfin restart
[root@<SERVERNAME> /etc/jellyfin $