Can't give user access to localization app

Hi there!

I have an issue with giving access to users for certain apps. I want for example limit the actions on the form app and give access to the localization app.

I have selected and deselected many things on the UI personalisation and permission tab but it looks like it is not responding. They have privilege settings as administrator but I cannot change remove permissions because it says:

"Selected user is administrator, therefore automatically granted with all permissions."

If I make him editor he cannot see anything in the admin and I don't want to give him no privileges or global because that's too tricky.

I have absolutely no clue how I can limit access to parts of an app and complete access to an app and how to edit the permissions per user role. How does the combination privileges, roles and permission work? And how can I achieve the above?