Adjusting the B-mag accuTrigger; get me up to speed

This has gotta seem a dumb question, but my accuTrigger doesn't behave as in instructions and non of the YouTube vids resemble what's in my B-mag. (Sorry my WSM is in another state so no pics), but the adjustment is a circular nut over the spring. When turning, it would just wind up the spring. Is there a small adjustment screw hidden down in the center that needs a small tool? (I hate black in black, eyes aren't so good) Instructions say to turn until it comes to a stop, but I think the spring is going to pop before coming to any felt stop.

Concisely, what little thingy needs turning and how does it feel? If it only adjusts down to 3lbs or so, can I take the spring out and trick it into giving up a little more, say 2 & half lbs?

Just turn the knob and you probably won't get any lower than 2.5 pounds. I would not remove any parts.

I can turn it but feels likes I'm just winding the spring tighter. Didn't have a trigger scale while there, but trigger still felt on the plus side of 3lbs. If I twisted it more, I could've had a permanently damaged spring. Turning it clockwise did increase tension for heavier trigger pull.
I'd be happy with 2.5lbs. So there's no little tool to go into the center of knob?

I can't say specificly on the Bmag, but that's the way other accutriggers work, the spring turns in or out to vary the preload on the trigger spring.

The little black knob revolves AROUND the spring itself. If you are twisting the spring one of two things is happening. Either the spring has bottomed out in the knob (end of travel) or it is hanging up and not screwing in and out properly (probably do to a poorly finished inner diameter of the black knob). If you are at the end of travel but still have a heavy pull it's probably related to the second problem above, the recess most likely wasn't finish well or deep enough for the spring to screw in far enough.