a cheaper option than the tool is to go to the hardware store, and buy a 1/2 square key stock. About $1. Then cut it down so it fits in the tight space, with a bit hangout out that you can grab with a wrench, vice grips, etc. Worked for me.

 

there is a square tab on the bottom of pulley mount to put an open end wrench or adjustable wrench on.i had the same problem couldnt get ratchet square in hole made for it then got the repair manual out and it said to use wrench on bottom tab.

 

I did not have enough room on my Van to get an wrench in there. I tried.

Bill