Let a gunsmith do it.
Highly recommend you ask a gunsmith for assistance.
Leave this to a qualified gunsmith, trust me on this.
HIghly recommend you leave this to a trained gunmsith.
Grab the cocking piece in a smooth jaw vise, pull the bolt and shroud foreward and unscrew the bolt. To re-assemble, with the cocking piece in the vise, push the shroud foreward and screw the bolt back on.
Download a manual from Browning or take it to a gunsmith
The browning web site will provide this info.
Do not atttempt this. Find a gunsmith.
Best left to a trained gunsmith
Best bet is to ask a gunsmith for help.
It is a bolt action rifle.
IIRC, you can get a manual on line at Browning's web site
This question is not answerable as Browning made dozens of different bolts.