I dont know what cwe is but ill try to explain to you how to get caffeine out of a codeine pill using acetone.
i checked the merck index and caffeine is soluble in acetone while it doesnt say that codiene is insoluble in it so it could be somewhat soluble in acetone, meaning you might lose a little if you do this. you need to be in an open place to do this, so if you are doing it inside keep the windows wide open and maybe use a fan.
heres what you do (take with a grain of salt, i might have left something important out)
1.crush pill into powder
2. put powder into cup (not plastic, preferably glass) and add acetone, dont use to much because you have to wait for it to evaporate
3. stirr the powder around, the goal is to dissolve the caffiene in the acetone
4. get a coffee filter and put the edges of the coffee filter around the edges of a cup, you might need to tape the edges of the coffee filter to the cup (but dont put the tape inside the cup, acetone melts plastic)
5. filter the acetone/codiene solution through the coffee filter and into the cup
6. the coffee filter should have some powder in it, this is the codeine sans caffeine. you have to wait for the acetone to evaporate before you use the codeine. It will probably take a long time, im not sure how long. You dont want to be ingesting acetone.
honestly i think you are going to lose a fair amount of codeine doing this, you definitely are going to lose some. im not really sure if this question is allowed because it isnt in the name of harm reduction that you want the codeine removed...