If the meth is in salt form, which it is, you could try using a small amount of warm water to see if the salt will dissolve into it and then evaporate it down. That should yield something more usable with little effort. Basically if you could somehow get the entirety of the weed meth mixture into some type of tube with a screen on it you should be able to get almost all of the meth out.
If you dont get what im trying to say look up how to make butane honey oil with weed using a tube and a can of butane, same idea except this time its water pulling the meth out of weed rather then butane taking the thc out of weed.