Booting Oneplus 2 android in recovery mode is one of the hidden features of this product, but this features gives option to perform operations like, factory reset, Wipe Cache, Wipe Data etc. Nevertheless there are two (2) ways in which you can execute this operation.
VIZ.
The hardware key method and
The use of ADB tool method.
Following the steps closing on each method , you we understand the process on how to boot any variant of OnePlus 2 device into recovery mode.
Method 1 >> VIa Hardware Keys
Power off your device.
Then press and hold Volume up button, and then press the power button together, and your android device would boot in recovery mode.
Method 2 >> Via ADB tools
>> Download ADB tools on your computer.
http://www.9jakeek.com/2015/08/how-to-boot-oneplus-2-in-recovery-mode.html?m=1