Humbucker Installation Help

I need some help with an upcoming Humbucker installation. I see some HB's have trim rings and some don't. I'm assuming when you use the trim rings, the pickup floats on the center screws to adjust pickup height. But how should the pickup be mounted if you don't want the trim rings? Do you screw the pickup directly into the body of the guitar, and if so, how do adjust for height ?

Thanks, Mike

With no rings, you just use wood screws and mount the pickup to the body.

For height adjustment, you can use springs on the screws, or a piece of high density foam under the pickup.

Or suspend it from the pickguardw/ a spring or surgical tubing around the screw to maintain the height.