He needs to have something to record his runs like Open Broadcaster Software or XSplit.
Then he needs a timer to time his runs, I recommend LiveSplit.

All your son needs is the Game, A Timer and some recording software.
Personally i'd reccomend Livesplit and Open Broadcasting Software, however they can be difficult to set up so i'd reccomend googling some guides on them.

Goodluck!

Speedrunning