You start by stopping exposure to mercury--Hg. That includes removal of "silver" filings that contain 50% mercury.

It is typically more comfortable to start with low dose DMPS, maybe 10 or 15mg every 6 or 8 hours along with plenty of antioxidants--Vitamin C & E. A variety of strange side effects are often reported by those who try to kick up Hg without plenty of antioxidant support.

After you've sufficiently cleared the blood of Hg you can add ALA without so much concern that it will move Hg into the brain and organs. That is what happend to the mice that were treated incorrectly with ALA in the Gregus study. Cutler commented on that here.
http://onibasu.com/archives/am/74605.html

Much more could be said.

Check out the symptoms under the 1000+ hair tests here.
http://livingnetwork.co.za/chelationnetwork/hairtest/hairtest22/

Cutler discusses the basics in his interview with Jo Davidson.
http://www.zentertainment.org/podcasts/zentertainment96.mp3

The Files and Links sections of the Yahoo detox groups have many tips as well.

Do your homework. Don't just jump in. Kicking up heavy metals can be dangerous if done irresponsibly. It can be life transforming when done carefully in a toxic person. I am one such person.