Nobulun

Hey, Yesterday I was going through every step from the maintenance guide from Ultimaker's website and i can't find any guide to calibrate your printhead. The topic related is this one: https://support.ultimaker.com/hc/en-us/articles/360011802280-Check-for-play-on-the-Ultimaker-2-axles. I've printed the calibration tool but idk how to use it. PD: Do you know which part of the printer must be changed after using it through the years? It's been 3 years since I've got the printer and it still prints like the first day (4.500 hours of printing). And I've only changed PTFE a couple of times, 2 Bowden tubes and 4 nozzles. Thanks!