boxers are essentially helpless if you attack or defend against them from the ground. They don't have a CLUE how to defend or attack a guy who is down there.
On your back, sort of, palms on the ground,but also on your feet, "crab" sort of movement by pressing down with hands. You can sort of scuttle towards a guy, he is unaware of the risk, then you use bottom of your foot, turned sideways, in stomping sort of motion, to bend his knee backwards.
you can "bicycle" kick to keep him off of you, one foot then the other, you use hands to swivel around on your butt, stay facing him. If he bends over, kick at his face or chest, if he sidesteps, use ball of the foot roundhouse kicks, if he gets close enough, use your spear hand to his face, or ridgehand to his temple. VERY few people know how to REALLY hurt you. Most hurt their HANDS a LOT worse than their little wussy punches hurt your head.
Once you REALLY understand that, and have learned to block, twist, cover up, etc, and have REALLY hardened your abs, you will laugh at unarmed people. But it's always best to ccw a pistol, in case one or more of them snatches up a chair or pulls a knife, breaks a bottle, etc. Then it's perfectly ok (legally) to shoot him, as long as he's within 10-12 ft, that is.