Refrigerator Compressor Replacement

I have a Whirlpool refrigerator that needs to have the compressor
replaced. The refrigerator currently uses R12. The replacement
compressor is a conversion kit to R134A. What is involved in the
conversion? Do I have to flush the system and how? Do I need to add
oil, and what type or is there oil in the replacement compressor? Do I
need to add service fittings and what type? I do A/C work on cars so
I'm familiar with the concepts. Thanks in advance!