Just a thought, I would try to loosen the alternator first. Especially the bottom swing bolt. I did the belts on an SD once and after I removed the the two front belts(ac and ps belts) I found the bottom alternator swing bolt was locked solid, no length of breaker bar would loosen it. Finally had to cut just one very split and loose old alt. belt and roll on just 1 new outer belt. So now I had one very tight new alt belt and one very loose old split back alt belt. Obviously not the job I had intended to do.

__________________
1981 240d
Newport,RI