Teleworker

Hi, I'm new to the forum....how annoying for you guys...to answer this question again!!!! i have a '96 AT Outback, recently i started getting a howling noise from the rear diff and it seemed to bind in sharp corners and reverse. The Subie dealership said I the rear diff was bad caused by a solenoid in the tranny......they wouldnt tell me anymore, it was going to cost $1700 to fix. I can't seem to fin the tech drawings or instructions on how to do it myself. I found a used rear diff...$350...can anybody recommend what/how it needs to be done...ant pics etc. Thanks Teleworker