Start by unlocking the Invincibility extra in the Extras menu using the in-game currency studs.
Activate the Invincibility extra from the Extras menu.
Once activated, you will become invincible and will no longer take damage from any enemies or hazards in the game.
To disable Invincibility, go back to the Extras menu and turn it off.
Note that Invincibility can be useful for getting past challenging sections of the game but may reduce the overall enjoyment of the game as it removes the challenge and risk of taking damage.