Go to a paintball store and pay for them to fill it.
At some sporting goods stores or any paintball field.
if you're asking how to refill the tank you take it to a local paintball shop or sporting goods store, they can fill them
You will need an all new regulator.
To refill a paintball tank, you must first go to a paintball field or store with a paintball air compressor. You can't refill them with just any home depot compressor, it takes serious pressure to fill these tanks. Find the fill station with the same pressure as your tank (3000, 4500 or 5000 psi) and hook up the fill hose to the fill nipple on the side of the tank while it is attached to your gun. Then press the lever or button in until the gauge on your tank or on the filler is at the correct pressure and release. Then unhook the fill hose.
At most Sporting goods, gun, and paintball fields. Some Gas (not just gasoline, but Ike propane) places you can fill your CO2.
You fill your gun with paint in the hopper. the CO2 or nitrogen tank pushes out "air" and forces a paintball through the barrel and at your opponent.
Where the air tank or co2 tank normally attaches
There is no paintball gun that runs on only 200 psi.
No they can not.
The sizes 9 oz and all the way up to 20 oz can be used for paintball gun. Some of the paintball guns are supposed to be used by the larger tanks. So the size of tank depends on your paintball gun.