Removing the valve from a helium tank is a fairly simple procedure that can be done in just a few minutes and requires no tools. The valve is screwed onto the top of the tank and just needs to be unscrewed after the remaining helium is taken out of the tank. Always keep in mind that helium can be flammable, so you need to work in a well-ventilated area away from any flames.
Push down on the black fill valve at the top of the tank in an open area to disperse any helium remaining in the tank. Let the tank empty out completely.
Turn the valve counterclockwise by hand until it is free from the tank.
Remove the valve from the tank and attach a cap to the top of the tank.