how do i fix brake lights?

Before investigating further, put the "new" bulb into socket that you know works. It's not unknown for new bulbs to be broken. If works then fault is elsewhere. As both do not work would suggest fuse for this corner has failed (sometimes happens when bulb blows) Check fuse box and should have markings indication which does what....should be either a red 10amp or blue 15amp. If no indication as to what is what, then a matter of checking each one by one with circuit tester

Strevs
April 2009