I have 2 questions about mounting a sling on my Xtrema 2 for anyone who has experience or knowledge in doing so. The gun comes with a front and rear sling mount. I'm not quite sure how to mount the swivel in the stock and the directions in the manual are not clear to me. There is a rubber bushing in the hole where the stock sling swivel goes and I'm not sure whether you have to take that out or you just push the swivel down on top of it. I tried pushing down on it didn't feel like it was going anywhere. And I also couldn't get the plug out and I didn't want to stab it with a hook or something to pull it out because that seems rediculous. My other question is that since the swivels are already on the gun(as opposed to being the little studs on most guns i've seen) does that mean I have to unstitch the loops on my sling and re-stich the loops around the beretta mounts? Why couldn't they just make it like any other gun?!?!?!?