Rcon lua ulx

Admin from my server made script.

When i make him admin, console back make him superadmin.

Where i can remove this lua script?

Delete his script.

Where i can find script?
He made it via ulx luarun

Look at the files in autorun (including in addons), and look for something like SetUserGroup, or an override of the IsSuperAdmin meta function.

You gotta love Russian grammar!