The Euro transmissions get pushed in pretty far, so it's going to take some work to get it out. I'd suggest if you have a Harbor Freight within reasonable distance, that is the place to get the punch set. I think mine was in the $10 range while PSI's is $20 or so (and in reality, they are just steel rods, and the sizes don't necessarily need to be precise, I can't say I've ever even seen if mine are labeled for size, I just grab one that fits...)
You will need to first find the largest one that will fit THROUGH the transmission. It will be larger than the tip on the refill, and use that one to knock out the tip end with a hammer (you can use one of those rubber "jar opener" grippers to hold your acrylic blank firmly in your hand. Leather also works good). Then find one that is the largest that will fit inside the main tube. If you're going to use a hammer for this one, you're going to need to hit it quite a bit to get the trans out, and in the end, it may get a bit banged up, so you MAY need to replace it (only happened to me once but it is possible...). What can work better is to take a 2 inch or so block of wood and drill a hole larger than the refill, but smaller than the pen body where the trans is. Then put the trans in the hole, so the pen body is against the wood. Put the punch through the end where the tip was, and sandwich the whole thing between your pen press, good clamp, or vice. This will allow you to put nice even pressure to push the trans out, which will be a lot less damaging than repeated whacking with a hammer...
