Hey, me and my brother played ESO together before. Now my brother quit the game, and i wanna do writs and dailies on both accounts. however the game wont let me log in on his account. Since my steam is linked to my original account.

I have tried launching the game through files, and not steam and that doesnt work

I have tried unlinking my own steam account, however i am then forced to link to my brothers account while trying to log in.

How would i be able to launch the game, and simply type in (any) userid and get to quickly switch between mine, and my brothers account?

I have my brothers full permission to play on his characters since he doesnt play any more.

We both bought the game on steam