What size socket do i need to attach to the ratchet to remove the caliper when im changing my brakes and rotors? thanks

1998 Lexus Gs 300

 

17mm or 19mm hope you got more tools than just ratchet n sockets

 

definitely want a breaker bar...
and turn the steering to the opposite side to give yourself room.
torque down to 95-100lb

also the short sockets wont clear so youll need an extension or a longer socket.

 

For the front, you need to remove 2 14mm bolts for the caliper, and 2 17mm bolts for the caliper bracket. If you are replacing the rotors, hit them really hard with a strong hammer multiple times before disassembly. That way they will easily come off when you take your caliper bracket off