Clear out the casemate (demand surrender, if no response grenade in first so the man who crawls through isn't an easy target for anyone left alive), take control of the remaining two guns, attempt to use them on what are presumably Belgian positions defending the bridges against the other assault groups.
Put a couple of frag grenades through the hole in the casemate. Destroy the other two guns from exterior, if possible. Maybe improvise a method of attaching the charges to the gun barrels, to avoid having to crawl inside the bunker (probably a bad idea).
The next bit would certainly be to go help your compatriots. Depending on the layout of the close defenses, though, it might be better off to go inside the bunker through the broken casemate and try to fight your way to them, rather than going over the top.
Clear out the casemate (demand surrender, if no response grenade in first so the man who crawls through isn't an easy target for anyone left alive), take control of the remaining two guns, attempt to use them on what are presumably Belgian positions defending the bridges against the other assault groups.
Put a couple of frag grenades through the hole in the casemate. Destroy the other two guns from exterior, if possible. Maybe improvise a method of attaching the charges to the gun barrels, to avoid having to crawl inside the bunker (probably a bad idea).
The next bit would certainly be to go help your compatriots. Depending on the layout of the close defenses, though, it might be better off to go inside the bunker through the broken casemate and try to fight your way to them, rather than going over the top.