Florian you need 2 tools in here,
1. adb fastboot command
2. firmware asus t00j from asus website format .zip
open adb fastboot command folder, put the firmware inside this folder and rename it user.zip for easy to type at adb command tool, in asus smartphone, get in to droidboot,recovery,adb sideload. connect ur asus to ur pc with usb cable, inside adb folder open windows command name "OPEN and type
"adb devices" hit enter, re type this until ur device listed if this okay, move to next step
type command "adb sideload user.zip" and hit enter,
hope this work for asus A500CG
