A demo on Youtube would be the best way to see how it takes-down and goes together. If I were to type a description, it would probably confuse some folks, and put others to sleep. In summary, when a lever is lifted, the two parts slide apart. Assembly is the reverse. There are no interrupted-threads, or such, just insert round peg into round hole, and close the take-down lever. I cannot say how well mine holds zero, after take-down and reassembly, because I have not yet mounted an optic, and, IIRC, have not yet done careful test-shooting. Several articles indicated that the return to zero was decent, and I saw this one on the pre-owned rack at a local dealer, when I happened to have a bit of disposable cash, so I bought it. This was several years ago.
A scope, if mounted on the receiver, in the conventional manner, stays on the receiver. There is, or was, a Browning-brand forward scope mount available, to accommodate an IER optic, which leaves the optic on the barrel when the rifle is taken-down.