During a recent bear hunt, I noticed that the windage knob on my rifle had moved after I took it out of the scabbard. I contacted Nightforce, and they promptly sent me a cover for it. However, I'm having trouble figuring out how to put it on. Initially, I thought the larger base would unscrew (see Red Arrow), but it won't come off. I tried to remove it, but after applying some pressure, I got worried I was going to break something. So, I removed the turret cap, and I found four Allen screws. I'm not sure if I need to remove them to continue with the installation. I've attached pictures of my issue. Any help would be greatly appreciated.