The link does still work. I actually found three different, very detailed articles on how to prepare the snails. They all agree on basic steps and vary just enough to be sure they weren't copy pasta.
Catch the snails and
feed them nontoxic foods for at least a few days (10-14 seems to be most common) washing the snails and replacing the food regularly.
Get rid of the slime with salt
water washing (some sites add vinegar, some do this before boiling some while boiling)
Boil the snails (anywhere from 5-15 minutes recommended)
Remove the meat from the shell and cut/scrape off the dark section where it was attached. If you don't destroy the shell in this process it can be used in the next step. At this point you could freeze the meat for storage until ready to prepare for a meal.
Most recipes call for baking for a long time submerged in herbed butter, usually in the original shells. Apparently you could also prepare them in any way you would traditionally cook mussels or clams. They're close relatives.
Oddly enough, my biggest hurdle here is that I don't like the taste of shell fish. I can also recognize bottom dwelling fish by taste. I suspect the long purge where the snails eat nothing but fresh vegetables and herbs will fix any flavor issues. The only time I had escargot in a restaurant it was extremely rubbery but the flavor was fine. Long cooking
should render them tender as well.