Frag Out! Magazine has a video showing how a Polish MSBS rifle can be assembled and disassembled.
Soldier Systems Daily also has links to the Frag Out! Magazine article as well
http://soldiersystems.net/2019/01/08/frag-out-presents-a-peek-inside-the-polish-fb-radom-msbs-grot-assault-rifle/
From: Frag Out! via Soldier Systems Daily