Slam him with the stall door.
From Create Your Own Story
"Okay, okay. You got me." You quickly pull your panties back up, got up from the toilet, and took a deep breath. You took the toilet paper off the dispenser and rolled it under the stall door against his feet.
"What game are you trying to...?" The moment that you sense him looking down at the distraction, you quickly flick the lock and kick the door open with full force. You hear a loud thud as the door violently ricocheted back towards you and slammed against the metallic lock.
"Ugh..!" You hear him groan, follow by the sound of a body falling to the ground.
You cautiously peeked out the stall and looked at the unconscious man on the ground, his nose bruised and bloodied from the impact. Looks like a younger guy, must have been in his early twenties like you.
What do you do now?
Disguise yourself as the guard.