help! broken belt tensioner

I need help! My 96 SC, 3.1, has a broken belt tensioner! Yep, the belt itself is fine, being only a few months old! My Haynes manual does not mention the tensioner, at all! Has this happened to any of you and were you able to replace it yourselves? I think you have to remove the upper motor mount and lower the motor, but I'm leery of dropping it too far, and damaging somethin else! Please help!

I need help! My 96 SC, 3.1, has a broken belt tensioner! Yep, the belt itself is fine, being only a few months old! My Haynes manual does not mention the tensioner, at all! Has this happened to any of you and were you able to replace it yourselves? I think you have to remove the upper motor mount and lower the motor, but I'm leery of dropping it too far, and damaging somethin else! Please help!
i had one go out on my 94 gran prix. it started flopping sideways. the belt was still turning. i figured it would break soon.the neighborhood shop charged me $65. labor. i guess it happens often or maybe because there,s so many 3.1 engines in the streets. auto zone stocks the part.i think the part was $45.???

[I changed on on my 95.
I supported the engine with a jack on the bottom.
removed top engine mount and belt

remove passenger front wheel
cut small hole in fender well to access bolt from tensioner and replaced it from bottom of fender well