How to revert to 16.04LTS
58888
Change Ubuntu 17.04 to Ubuntu 16.04.2 LTS
99175
How to "undo" SetOptions (restore defaults)?
42247
how do I go about removing all the language packs I don't need
26167
What is the easiest way to strip a desktop edition to a server edition?
27831
Can't downgrade database from version 2 to 1
23582
How to revert to GNOME Classic Desktop?
78859
How to reinstall default packages
141556
replace default Dutch Thunderbird by en-US version
98615
Is it possible to switch Ubuntu back to base-2?
1687
How to revert software sources back to default?
2045
How to get my file back in 2.79 after saving with 2.80 series?
105231
How to downgrade a package using dpkg
42078
How can I undo the last cd command?
119334
How to set Python back to the original version
33540
How can I switch a 32-bit installation to a 64-bit one?
100135
What does "upgrade to 18.04" mean?
17812
Restore database from backup file of different version / edition