Beam aligment

Hi anyone know or can send me something on how to do a beam alignment on a gravograph LS500XL thanks

I have no experience on the Gravo, but the physics should apply to all.
This guy explains well, kinda long but worth watching.
Make sure you have triple checked yourself for safety, know what you are about to change, and above all KEEP NOTES!!
Hope it helps.

https://www.youtube.com/watch?v=e1c3keOKL6Y