[Gimp-user] How to revert to version 2.6 in Ubuntu

[Pietro Calogero <pietro urbanpolicy net>]

Hi all,
I need to revert to GIMP version 2.6. Please tell me the proper BASH 
commands to do this in an Ubuntu system.

Evidently I am not the "power-user" type for whom the GIMP team designed 
their 2.8 version.
I only have about 20,000 photos, and I need to revise the JPGs or 
preferably work with PNGs.
I tried resetting the <ctrl><S> keybinding to "overwrite," but even so, 
every time I close a file (about 25 x/day) it warns me that I have 
unsaved changes--because the GIMP PolitBuro has decided that only XCF is 
worthy, not my miserable uncompressed PNG (which is what I can use for 
my academic presentations. Default image viewers in 
Ubuntu/Kubuntu/Xubuntu don't read the XCF format).

So I need to revert to version 2.6 in a responsible way (repositories, 
dependencies, etc) while I wait for a fork to emerge so that I can 
switch to a full-featured raster editor designed by a less-condescending 
team of developers.

Pietro