I own a 2002 chevy cavalier your cd player stopped working and now shows error and the motor sounds like its constantly running? can i buy an aftermarket and the easiest way to put the new radio in

 

Yes, you can buy an aftermarket...and the installation kit, harness and chime adapter. EASIEST way: have somebody else install it. (haha)
Removal involves taking the WHOLE top of the dash off. Not hard, just a little time consuming. once you have the OEM radio out, I'd try to save some money and work and
take off the top and remove your cd. take a look around inside, see if any of the rubberbands seem to be off, gears in place etc. Plug it back in and try another cd.
If that dosen't work, go with another stereo. I'll sell you mine for $20 plus shipping
As for an aftermarket stereo... I'd recommend Crutchfield. They give you the diagrams and instructions to get the dash apart for free.

 

crutchfield is good but ive noticed a bit spendier than a few places

 

Trust me, I'm as cheap as it gets, but Crutchfield is worth it. The instructions, the lifetime tech support, and quality accessories. Shipping is usually free too.