how to disassemble front and rear speaker's

Dear cg;I've been trying to change the factory speaker's in my camry to high performance speaker's.But the problem is that i'm not sure how to take the back cover's off and i don't want to break the cover's.And the door speaker's are kind of confusing because when i tried to remove the screw's on the door pannel it still would'nt budge.Car gurus please step by step explain to me the correct way to pull off the dorr pannel's without breaking anything and tell me how to remove what ever i got to move to take out the rear factory speaker's without waisting money.Because i'm good at those sort of thing's but this is my first toyota and it seem's that certain thing's disassemble way different than other's though it may seem that it disassemble's the same way expecially with american car's their more simple.Please contact me asap at afdiggs1@varizon.net