My 93 buick regal custom 3.8l has a bad ac pump and makes an aweful noise when running. The ac doesnt work and the 'clutch' on the pump spins freely, is this an easy fix or do i need a new ac pump?

U will need to replace the pumpand the front pulley bearing to repair this, u can buy this pump with a new clutch and pulley on ebay very cheap. here is a link to an auction for the compressor u need.
U don't say engine so there are links for both compressors, the 3.8 and 3.1 V6's
http://cgi.ebay.com/ebaymotors/New-AC-Compressor-1993-Buick-Regal-Limited-3-8_W0QQcmdZViewItemQQhashZitem5ad78fa0d7QQitemZ390163570903QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

http://cgi.ebay.com/ebaymotors/New-AC-Compressor-1993-Buick-Regal-Limited-3-1_W0QQcmdZViewItemQQhashZitem19bace6fceQQitemZ110508273614QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

You would need a new a/c pump, however you you didnt want to replace it and could live with out the a/c, a cheaper option is to replace the belt and bypass the a/c. Most auto parts store will sell you a belt of the correct dimensions if you tell them you wish to bypass the a/c. I've done this for many customers. It can be done on just about any motor.

Best of Luck.....