When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
There is no easy way to adjust the parking brake.
1) Remove wheels, caliper, caliper bracket and rotor
2) Ebrake handle in OFF position, Rotate star wheel on adjuster to expand shoe closer to drum inside of rotor - star wheel is at the open end of brake shoe
3) Test fit rotor - drum should just barely make contact with shoe, if not expand shoe with adjuster and test fit again.
4) Reassemble and do the oher side.
Your brake should hold the car firmly when handle is pulled up 5-6 clicks
Have you considered sending GM an e-mail asking why they couldnt put a hole in the brake rotor so you can access the adjuster, like every other car seems to have?