I have a quantum accurist AC500PT and i want to put some oil on the gears because it is getting a little old. However, on my handle side, the side plate won't pop off even after taking the screws off. Does anyone know what the problem could be? Im getting very frustrated.

make sure ALL of the screws are out. you might have to remove the small rod that the levelwind rides on and there should be one or a couple of screws behind the spool on the handle side. I don't know if you have already but you have to remove the handle and drag star as well.

You put grease on gears and oil on bearings.

http://www.tackleservice.com/bps/tackleservice/zebco/knowledge/ac500pts%20schematic_f86cc5dd-0_.pdf

First off, don't open any reel unless you have a schematic in front of you. Quantums are a PIA to disassemble. The nose piece in front of the level wind needs to come. To do that you must remove the support bolt screw and slide the nose piece forward while holding the side plate release open. The release is spring loaded and there is at least a 50/50 chance of loosing it your first time. I believe there is one more screw holding the side plate from the back that you can then access.

I highly recommend sending the reel for a thorough cleaning and lube.