Help replacing alternator 1998 Golf

Has anyone replaced alternator in 1998 Golf?

I was wondering how to release tensionor pulley.

It looks like the spring is on the other side of the alternator. I think maybe there is an allen bolt that tensions the spring to release the pulley.

Can anyone help me here?

There is a threaded hole on the upper side of the tensioner that a long 8mm x 1.25 bolt will fit. Tighten the bolt to release the tension, but do not over-tighten as the threaded metal is soft & will crack if stressed too hard.