Theres quite a few ways to cook it.
Its basically evaporating the liquid into crystal/powder.
If you're not in a rush (and the most fool proof way) you can air dry it.
Pour (or pull some up in a syringe and squirt) a quarter or half a vial (or all of it) onto a ceramic plate or glass dish and leave it on top of a cupboard for 24hrs. When you come back to it the liquid will have evaporated off and then you scrape it up with a card or razor and chop it finely like you would cocaine, then snort.
To do it quicker put it on a plate then place the plate ontop of a saucepan half full of boiling water. Takes 30-45 mins ish for 1000mg. Basically when you see the bubbless stop moving around under the surface it's done. If you take it off and its damp/clumpy when you scrape it, put it back on for longer. Keep an eye on the water level in the saucepan it may need a top up halfway through.
Or in a glass dish in the oven on medium heat with the door open but that takes longer. But does yield nice big crystals.
Even quicker put the liquid directly into a frying pan and cook on medium heat only takes a few minutes, but beware you can burn it and ruin it this way.
You can also microwave it on the plate 1000mg would cook in 1 minute, but you have to cover the plate with another plate or it will spit all over your microwave and you'll loose loads. Just remember to leave a little gap in the plates for the steam to escape.
Sounds like you arent in a massive rush if you haven't tried it yet so try the air dry. It'll go quicker if you leave it in an airing cupboard or on a radiator or by the window where the sun will hit it.
They say the longer you cook it for, the stronger it is
also makes the crystal/powder 'lighter/fluffier'
I do agree, microwaving it does seem to take some potency away, and yeilds hard white powder.
Frying pan takes some practice to get nice results. Noobies will be left with white hard lumps of powder, if you get the technique down you can get steam plate/oven/air dry type results in minutes. But thats a whole different story lol.
Steaming (plate over saucepan) the yeild is more crystally, and lighter to snort once crushed. Oven is again bigger crystals and lighter to snort, air dry is the best. I used to have loads of pics of different cooks/results but they're unfortunately gone now.
Hope this helps mate.
Theres loads of info online about cooking it.
But if you have any other questions just ask me! I've been cooking it for probably 16 years.
Good luck with the WDs let us know how you get on if you try some.