How do you rebuild an AC compressor for a car?

To be totally honest (and realistic), don't waste your time or money rebuilding it yourself. Although prices on replacement compressors may sound ridiculous at your local parts store, they are worth every penny. The average guy, and most shops, do not have the means or equipment to rebuild them first hand. You'd have more invested in specialty tools/equipment alone to rebuild it yourself than it would cost to purchase a rebuilt unit! Just not cost effective.