The brake light switch is under the dash and activated by a stop on the brake pedal arm you will need to remove the knee bolster to gain access to it.
As far as the back lights it may be the switch on the trans. believe it takes a special tool to change it out.
http://zr1.net/backup.html
The service manuals can be ordered from Helms I’m sure they have a web site. Sometimes they come up on ebay .
http://www.helminc.com
Steve