OnePlus has finally released Oxygen OS!
This tutorial is noob friendly, so it's very easy.
If you have any questions, just ask ;)
Links:
Toolbox: http://inthiaano.com/oneplus-one-toolbox/
OxygenOS: https://forums.oneplus.net/threads/o...-guide.289398/
TWRP: http://dl.twrp.me/bacon/
xda-developers