toyota premium sound speaker size

i took the door skin off a 02 toyota sequoia with premium sound. my mission was to change the woofer. well i have 2 questions. there is one 7" woofer 1 tweeter next to it and one tweeter up high. where are these speakers frequencies crossed over, the amp? how is everyone else dealing with this problem(changing old woofer) when the speaker size is not 6.5". is everyone bypassing facotry wiring and ditching the factory tweeter? where can you pick up a full range frequency? what size speaker do i use or are there adapters?owner of

Motion Marine & Car Audio

the florida keys

I ran  my factory premium sound 01 celica speakers off of a rockford 600a4, and they sounded great. I made an mdf plate when I swapped them out for some arc audio componants.