Austin83

I purchased a used plastic bumper cover to replace the dinged up bumper cover on my 09 Toyota Tacoma. The used bumper I bought has some paint chipping on an inside edge near the plastic grill (only an 1/8 of an inch of paint chipping around that grill). This bumper has the Toyota factory single stage white paint. I figured I will tackle the job and work on preparing the bumper to be re-painted. Do I need to sand ALL of the existing paint down to the plastic before spraying with primer? Should I start wet sanding with 220? I am not in a hurry and I have time to work on it in the evenings while at work. Any advice is appreciated.