use the 25g pin as an air release in the vial you are putting the tren into. Just put in in the rubber stopper and leave it there. The 18g goes on one side of the filter. The syringe goes on the other side. This is what you want to do.
Place 25g into new vial.
Draw tren into the big syringe using an 18g ( or larger ) pin.
Leave that pin in the vial that you are drawing from and simply unscrew it from the syringe. This will keep the large gauge pin from ripping the stopper and causing little pieces of rubber to break off.
Take another 18g pin and screw it onto the bottom side of the whatman filter. (the side that's going into the new vial)
Screw the large syringe that you just filled onto the other side of the filter and slowly push the filtered tren into the new vial.
Then leave the pin with the filter in the new vial. Once again, this will keep the stopper from tearing and leaving pieces of rubber in the new vial.
So, just leave the pins where they are and switch the large sryinge back and forth.
Any questions?