How to prep/sand bumper covers for paint???

I need to have both the front and rear bumper covers painted and I wanted to do the sanding and prep stuff to save some money. Can anyone help me out with the best way to do this. I would like to have everything done and just take it to someone to paint them. Thanks.

if they are not in real bad shape use a DA with 1500 grit

You can get plastic bumper stripper from a paint store, it's like spray paint. Spray on thick, scrape off old paint.

Then you can primer with whatever, and wet sand it smooth. Make sure you get it all even too, no low/high spots. That's it! Good luck.