need part name and how to install
 

Hello everyone.This is my first time on this site and need some quick info.I have a 1994 Villager.My ac belt broke. There is a pully that also "rides" with the ac belt. Is this the "idler" pully? I need to replace this part as it is siezed along with the ac belt.I just don't know if I am asking for the right part.Also how easy is it to change the part and install the belt.Going on a long trip saturday so I would like to do this asap in the morning.Any help is appreciated.Any short cuts,can it be done from the top?
I am used to working on cars,not vans.Thanks