What happens if you open a new depository, perform an update, but do not install the application itself that you planned to install?

Question

KDE

In general, I wanted to upgrade kde to 5.8, it was kde 5. I found out about the release of kde 5.8 from compizomania.blogspot.com/2016/10/kde-neon-58.html?utm_source=feedburer&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FfXuio+ (compizomania) and decided to update. I updated according to the instructions losst.ru/kde-praznuet-20-let-vypuskom-kde-plasma-5... I found out that at the moment kde 5.8 does not support the Russian language and I need to update it. Tell me how can I return everything to its place, return the old repositories and updates