Re: getting amalgams out... the wrong way.

Although I disagree with your decision (I would keep the Amalgam until I could afford it), if you do go ahead with this, do take activated charcoal prior to the appointment (~15min prior); once you get out of the office I would rinse your mouth for a couple minutes with a combination of activated charcoal and chlorella (spit it out afterwards). I would bump up the daily dosage of vitamin C for the coming weeks.
Do ask the dentist if rubber dam is available (he should have) and if constant water jet is applied to the site as he drills it out (to minimize mercury vaporization).
Obviously vacuum is required.
Mike