That is a good question-- I hope someoen may know what to do.
I also have two tattoos-- one on my lower back (a butterfly) and one on my shoulder- ( a smaller butterfly) At the time I got them , Mercury never crossed my mind.
To get them removed with laser would run into over $1,000. My first agenda is getting my metal fillings removed first!
I wonder if the tattoos will rid themselves of the mercury in a short time- especially if you chelate the mercury out of your body.- (unlike silver Amalgams that release mercury vapor for over 50-60 years and more- even after the person is in the coffin)
From what I recall on this question over at the Ask MH Forum a few months ago, MH suggested using one of those Black Salves. You can order Dr. Christopher's Black Root Salve online -- they have thier own website. I ordered other things from that site and got them very quickly.
I also wonder if you could try bandaging chlorella, crushed cilantro, and other mercury chelating substances made into a paste onto the tatoos and do this every night for over a month or so.
It may not remove the tattoo-, but it may leach out the mercury that was used in the dyes into the bandage. I do know that the body seeks to releaase mercury out of the skin pores. At least a tatoo is right at the skin and I would say that applying those toxic metal chelators directly on the tattoo could only help move the mercury out faster.
You may also want to try some of those foot detox pads that they sell. Apply them to your tattoo instead of the feet- I got some, and they do really draw alot of toxins out.