how do you get the idler pulley off?

I have a 95 Aurora. Ok, my idler pulley has been bad for some time now. It makes a whirling sound. But looking at it, it is so close to a plate, there is no way I can get it off. The plate is connected on one side to the engine and on the other side to a motor mount. It looks like if I take the plate off, that side of the engine is going to fall out the bottom of the car. That's another question. Looks to me that the accessory belt is going around the motor mount so to change out the accessory belt, I would have to disconnect the motor mount which the engine would fall out of the car. Am I seeing something wrong? So the real question is what is the right way to take that plate off when I replace the pulley and in case I ever have to change my accessory belt?

Serp belt threads in without touching the torque plate. For the pulley, remove all the bolts you can. Remove the motor mount pin bolt. Only the bolt holding the plate to the frame way down at the bottom can stay. It will flex enough to allow you to pull the plate away to remove the pulley shaft, which threads into the block. Support the pulley side of the engine from underneath using a floor jack. I think that's about everything.

But even after I get the belt off, how am I ever going to get the idler pulley off with that little space in between the pulley and the plate?