Unless you have some A/C experience I do not recommend attempting this yourself.
First off any remaining refrigerant ( If any left) would need to be evacuated.
Then once the condenser is replaced, the system needs to be pulled into a vacuum to remove any moisture in the system and see if there are other leaks. If the leak was significant enough and left for a long period of time, the dryer might need replacing since its been exposed and the A/C will not function properly.
Once all that is fixed the system gets charged with the right amount of refrigerant and lubricant if any is needed that is recommended for the vehicle, usually there is a sticker under the hood.