To return EVO 4G LTE back to factory:


Get the fastboot files here:
http://androidforums.com/evo-4g-lte-all-things-root/606748-how-install-kernels-s-h-boot-1-15-a.html

ReLock the bootloader if its "Unlocked" following this guide:
http://forum.xda-developers.com/showthread.php?t=1231249

Windows HTC drivers, RUU (stock rom) & guide here:
http://theunlockr.com/2012/05/29/how-to-unroot-htc-evo-4g-lte-smartphone/