Here is what I do:
1: Have a sterile empty vial ready for the solution
2: Score the necks of the amps with a butter knife
3: With a towel, break off the necks of the amps
4: I use a 1.5" needle since the amps are fairly deep, suck up all the solvent from the one amp and squirt it into the amp with the powder.
5: Suck out the solution and squirt it into the empty sterile vial
6: Draw up a ml of bac water and put it in the amp that had the powder, i squirt it down the sides of the amp to make sure all the powder is off the sides. Then suck it up and put it in the vial. I usually do it again with another ml of bac water to really make sure I got all of the HCG powder.
7. Add as much bac water as you need to the vial to get the concentration you want. I usually mix mine to 500IU/ml, so with a 5000IU amp, I add the 1ml of solvent, and then 9 mls of bac water for a total of 10ml of liquid making it to 500IU/ml. Makes the injections of 250IU just .5ml which are really easy. Next time I will probably mix mine to 1000IU/ml for an even smaller injection volume. Its pretty simple, just make sure you keep track of how many ml's of bac water you add! Just simple math to figure the concentration you want. Hope that helps.