how do i splitpush

Ward jungle, kill minions, kill towers, don't die.

enemy team tries to kill you, run, go back after they leave...

Rinse repeat, win game

as long as you don't die and applying pressure you are doing I right

Also pray that your team actually takes objectives when they send 4 people to kill you.

Know where the enemies are, if they go into the jungle or something then leave/recall

Run down lane and die over and over while ignoring your team. If they demand help in teamfights, say you are splitpushing to win the game.

more debatable is 'when' to split push