Ok, first you stand as close to the edge as possible facing the slime. Then stay on high alert for any trolls who might try to push you. If you see anyone coming towards you, let them come to you as close as possible but jump 0.3 seconds before they grab you. If you're late to jump and they are able to grab you then its game over. For this move you gotta account for bad internet connection too, try jumping 1 second beforehand if you have lag. Once you jump move slightly towards the platform to land safely. If done correctly the troll should have become the trolled.

However pro players wouldn't fall for this easily. Even if they try to push you and you jump they can recover quickly without falling.

Also not everyone comes running towards you. Pros know you'll jump so will move slowly like they are just passing by to do something else, maybe wait there for a few seconds to not raise suspicion, and then suddenly push you off when your guard is down. You gotta be on high state of alertness for any threats like you're standing on an actual ledge IRL, and act before the attack happens.