gas station. Most have air hoses but not the right attachment. You will need to rig it up to a rubber valve stem. You could also use a bike pump which will build enough pressure to blow it out. I've used both these processEs in a pinch. But have something soft to aim the piston into. It can build enough pressure to be dangerous or damage the piston.
" I told my son, you have to catch the football other wise this just looks like child abuse." - My brother