Replacing an air conditioner compressor is a complex task that requires specialized knowledge and tools. It involves removing the old compressor, brazing in a new one, and recharging the system with refrigerant. If you are not comfortable working with electrical systems or handling refrigerants, it is best to leave this job to a qualified HVAC technician.
That said, if you are confident in your abilities and have the necessary tools, replacing an air conditioner compressor can be a rewarding experience. Not only will you save money on the cost of labor, but you will also have the satisfaction of knowing that you have completed a difficult task.