How to remove the right-side tool panel?

[dacq]

I moved onto gimp 2.10.21 from an older version, where the tool panel was on the left only. The panel had all the features that the new one has on the right side.

[Ofnuts]

You can just drag things from the right to the left (drag by the tab). You can also add tabs in exiting "docks" using the < icon at the end of the tab line of a dock.

[rich2005]

It might help if you give information on the old Gimp version (Gimp 2.8.something perhaps)
and your version of linux because Gimp 2.10.21 is now very old latest is Gimp 2.10.38

If you did upgrade from Gimp 2.8 to Gimp 2.10 some of the old setting are migrated and you can reset the interface

Edit -> Preferences -> Interface -> Window Management then click on Reset Saved Window Positions to Default Values

If you used an old version of Gimp in multi-window mode then that is a different story. Give details of the layout.

A couple of very old videos on moving Tabs around but still valid:
https://www.youtube.com/watch?v=PFvV6b2Og7o
and https://www.youtube.com/watch?v=01PeLL1F8Kg

[dacq]

Thanks Ofnuts that did the trick.

I was using 2.8.10 before but installed Mint 21.3 recently.