Hi, I was trying to change the front speakers in my 69 vert located in the kick panels and thought the grill would pop right off, but it didn't. They seem to be made of metal and are a factory option so they may have been on there for 36 years now (they sure sound like they are 36 yrs old) can anyone tell me how to remove them without damaging them? Also can they be replaced with a standard size speaker I can get easily at a local store? Thanks Pete