Desperate help with beer keg

Got 39 pints of nice tasting John Bull in and the tap is dripping......help?

Could I release the top to let out gas, the beer comes out foamy, or do I throw a beer party?

Throw a party  wish I lived by you 

I'd syphon it into a fermenting bucket then tighten the tap up, test it with water and co2 to see if it can take pressure without leaking then syphon the beer back into the keg, either put co2 back in or reprime with sugar, hope that helps

I usually use 3oz, you don't want too much or you'll get too much carbonation.
You could fit a small pressure gauge to your keg then you can keep an eye on it and release pressure if you need to. Cheers