messed up ITR

ok guys......i need advice from all you fellow modelers....:D
my friend has a messed up model that i offered to paint for him..... it's a revell ITR.....(so popular).....there are some scratches ( a few big ones) there's some paint on it......like.......the paint is spotty.....like it's only on some parts......and i tried wet sanding it, and it won't come off......he told me he used r/c car paint.......i don't know what i should do first......can someone guide me through the process of what i should do before i start primering?.......
and yes guiddy.......i will be primering......you have convinced me.......:D

Sounds like you will be best off by stripping all the paint and starting from scratch. You can use Castrol Super Clean (CSC) or maybe brake fluid or oven cleaner...

There've been lots of threads about using all of them. Check them out with the "Quick Search," then ask any other questions you need... :)