Well it should be a simple as removing you dumpy ASA leaving the hose and pushing the hose into the Armaggedons elbow. Fill up you tank
and screw it in and make sure your output gauge on the geddon is around the 500 psi mark.
If your have problems.... firstly check air is coming out of the Geddon. . slowly screw bottle in and air should come out...next unscrew the inline reg so the whole air system (geddon and inline) is off the gun, and slowly screw the bottle in again, make sure air is coming through the inline.
If there ok, then the next thing to check is that if the LPR is an externally adjustable variety you ain't accidently turned it right down so stopping it from cocking the gun.. . .test this gas it up and cock it manually then fire it... if sounds normal then you need turn you LPR up.....
if not ermmm dunno without looking at it.....
Oh yeah i wouldn't bugger around with the inline, otherwise you'll need set it up again. . . .chrono and paint required. . .