I was talking with a neighbor after supper and he said the easiest way he knows is to dump your magazine before the last shot and slap in a fresh mag. You may waste a round or two that way but it sounds good to me.
He’s tried other methods and wasn’t able to get the slide back far enough to reload a round. He’s changed magazines, then held onto the slide with his free hand and was able slide it back. He didn’t like that method because he felt it was too dangerous.
If its got a slide lock, why waste the rounds and possibly cause a feed failure from a weakly inserted mag ?
OTOH, if not a locking slide, and IF its a 'must do one handed', rake the rear sight on a belt or pocket ??? as safely pointed as possible of course
If a bg is comin anyways, Id rather risk shooting myself than lettin him do it fer free...
my .02