Carry a lunge whip or a dressage whip, whichever may be easier for you to use.
When they go to kick or bite, whack them good for the bad behavior, let them know you're in charge and not to be messed with.
Make them face you and submit to you, do this each and every time they act nasty and go to kick or bite.
If they let you get close and then try to bite, have a smaller whip in your hand and have the handle of the whip facing them, as they go to bite, bring the handle up and let it hit them in the mouth a bit, not forceful, let them run into the whip handle themselves. They tend not to like the feeling and will stop.
Also if you are unsure of using a whip, make sure you're fast enough and use your hand, a nice hard smack to the shoulder, hindquarter or neck and a loud reprimand like a loud 'NO!', or a buzzer like sound also works.
Instead of the whip to the mouth thing you can also deploy a nice stiff bristled brush for the same maneuver. Let them run into the hard bristles, again, they don't like the sensation and tend to back off.
Finally ask the owner if you can work with the horses out of the stall to work on ground manners and you being in control, if he says yes, then get a lead rope, a lunge whip or dressage whip and begin leading and moving them, make them move, let them know you're boss and bad behavior will be reprimanded.
I worked with a horse with nasty habits, nobody worked on correcting her until I started it, she'd try to run over me during leading, she'd get an elbow jab to the neck or shoulder each time she came over on me.
If she pinned her ears at me coming into her stall, I'd stand there whip in hand and not let her eat until she submitted to me, if she came at the bucket, she got popped and moved back. This applied to being in the field as well.
"They see me rollin, They hatin, Patrolling they tryin to catch me ridin dirty"