2.) You have to check the md5 sum! It should match this exactly. 8e166e93a9a72cb7955440720ba8869a
If you don’t know how to check the md5 sum watch the beginning of my video Here
3.) The file is already named correctly, so you just need to place it on the root of your sd card. Not in any folder or subfolder.
4.) Shutdown your phone. Then hold the volume down button and the power button until your phone boots to the bootloader. It should then find the zip file and ask you if you want to apply the update, select yes (volume up). It will flash, then tell you it was successful and push the power button to reboot.