Quick question
 

Hey everyone. this is my first post, as i have just purchased my first audi. i got a 98 a4 2.8l quattro, and it is the nicest car ive ever owned.

my only real problem with the car is, the rear speakers are blown. i want to take them out and replace them. i was wondering if anyone could tell me how to remove the rear speakers without breaking anything. What size speakers are back there? Also, will i be able to just swap in some aftermarket speakers or will i be fucking up some bose stock amp.

thanks!