Regain Root access on Asus TF300T after official update 10.4.2.13

So i downloaded and installed the official 10.4.2.13 update from the Asus website. After this i had no root access anymore (as expected). I found a few manuals which described to regain root access which includes to download a file of 400+ MB. There is a simpler way to regain root access:

• Install TWRP: http://teamw.in/project/twrp2/97 (use the fasboot method)
• Boot into TWRP (hold power and volume down, select recovery using volume down and confirm with volume up)
• Flash SuperSU (0.93-Busybox-1.20.2 in my case)
• All done

Good Luck!