How to reinstall android to the fresh stock?
If it's not rooted and not running a custom ROM, a factory reset will reset everything back to stock and wipe the internal SD card.  If you also wipe the external SD card, you will have a clean slate.

Checkout Chapter Update and Reset, Section Resetting HTC EVO 3D, (Page 209) of the manual: http://www.htc.com/managed-assets/support/user-guide/user-manual/htc-evo-3d/110803_ShooterU_HTC_WWE_UM.pdf

Quoting the manual:


  Resetting HTC EVO 3D 
  
  Do a factory reset to return HTC EVO 3D to its
  original state before the first time you turned it on. 
  
  If you’re passing HTC EVO 3D on to someone else or HTC EVO 3D has a persistent
  problem that cannot be solved, you can perform a factory reset (also
  called a hard reset). Factory reset is not a step to be taken lightly.
  It’ll permanently delete all your data and customized settings, and
  will remove any applications you’ve downloaded and installed. Be sure
  to back up any data and files you want to keep before you do a factory
  reset.