I remember that I had to apply so much force to get mine off the first time, I thought I was definitely going to break something. But, I was following springfield's directions, and I knew the thing had to come off. I had to tap the wrench with a hammer to get mine off.
Definitely no reason to clean it yet though, like has been said as long as your piston moves freely.
If you do take it off, you should shim the gas cylinder for sure. This is the only reason I took mine apart to begin with, and it increased accuracy about 30% on mine. The gas system is not unitized on a "loaded" and shimming it (which is a very cheap and easy DIY project) helps with accuracy on most rifles. You can look it up on YouTube for directions or go over to the m14 forum.
Be warned- these rifles are addictive. I just bought another one that was in our local paper for too cheap to pass up. It's a NM M1a and the guy had bought every accessory there was at the time I believe, one of which was a bore guide for a cleaning rod that slips into the muzzle. I had previously been following Kraigs advice about the shotgun shell. Btw, he knows what he's talking about and always offers solid advice on the m1a platform.