I got the generic wormer (pyrantel pamoate/praziquantel) tablets from here http://www.petshed.com/products/category440.asp

The dosage is 8mg/kg of prazi and each pill contains 50mg.

So.. say you have a 1 kg snake:

1kg X 8mg = 8mg
8mg divided by 50mg in the pill = .16 of a pill. Grind a pill up and mix it with 1cc of water and draw up .16cc and there you have it.