Originally Posted by
Hocam
What are you 12 years old? If not, stop acting like it.
You've got a good idea with the pump but you need a way for the air in the tube to get out. I'd cut a hole in the opposite side of the tube, then fill it most of the way with water with you pump idea. If it's dry enough and you didn't fill it too much, you can patch the cut on the tube and reinstall on the bike. Then maybe you can add some extra water to make it seem like the tires aren't flat.
If you started with a new Tube, or took an old one and rolled it up first most of the air would be gone. If you filled them about half, you could still mount them, then finish with air.