Go grab some 800, 1000, and 2000 grit sand paper, and a squirt bottle with water and get wet sanding!
Just work your way up from the 800, basically you want to knock off the nasty stuff with that, then refine that once it's smooth with the 1000 and 2000.
After that, just get your self some meguiars paint polish and start polishing.
Just whatever you do, don't buy the turtle brand polish, it doesn't cut unless you have a nice right angle variable speed polisher, the meguiars stuff you can do by hand and get results WAY faster... You'll thank me later.
Oh, and look at it this way: The paint is already bad, so you can't screw it up more by trying... You can only make it better!