Some pictures, step by sptep to help!
PUT YOUR PHONE ON FASTBOOT MODE AND PLUG IT TO YOUR PC! (truned off, press vol+ and power button)
- at step 5 you have to browse your files and select the "usb_drivers" folder that you just downloaded then choose "Let me pick...".
- at step 6 it appear "asus android device" in my case but DONT care about that. Select "all devices". The next step is the important part.
- at step 7 click on have disk and browse to your usb_drivers folder
After this you can use commands to root, flash new recoveries, and go back to completly stock using bootloader mode on your device.