How to remove polish/wax from a car

Hi everyone,
I have just collected my car from someone who was supposed to compound it to remove the oxidization of the paint (its red so it was patchy pink especially the bonnet, roof and drivers side) and wax it but it looks absolutely terrible. I suspect he only used coloured polish because it is all over the trim,lights etc and I want to strip off his ****** job and redo it myself. Other sites suggest anything from wd40 to peanut butter to clay bars to remove the polish but I thought I would get some advice from the kind folks here (again).

Also, I have an orbital sander and have been told that I can use that to compound and then polish the car. How do I get rid of his ****** job, remove the oxidization and then polish the car properly?

Thanks in advance to everyone for their advice and help.

Yours
Patdoll