it's pretty straight forward D, you freeze your trim inside the thermos about 2/3 full or however much you want to but 2/3 full is about the top you want to push to. i took the cap bit off the thermos and put some bigger drain holes through:
screw it back on the thermos
blast a couple of tins of butane into it ( which is re-usable if your doing double thermos runs btw).
run it through a coffee filter or similar just to keep the stuff in the thermos:
then ban marie it or for the non kitchen fire enthusia let it evap naturally...
then when it's almost all evapped or if you want to i guess you could purge it at this point but i don't bother i just gently heat a couple of times while it's still fairly liquid then mix in the ethanol and put it back in the freezer overnight or about 8 hours if your in a rush.
then take the thing out again and coffee filter it again but into a bottomless jug:
it's easier to tape the filter in place or peg it fyi
put it back in the freezer to drip through and your left with all the waxy plant fat stuff in the filter and nice clean oil in the pyres which you just evap naturally.
and that's that start to finish. i have neglected to tell the missus where the tea towel has gone missing too and why the bin smells funny.