So you happen to finally get your hands on the 2014 Flagship Killer, The Infamous Oneplus One! You turn on your new phone and ready to take advantage of it. Then realize the phone out of box you still need to unlock the bootloader, root it and install a custom recovery but no sure how. Well dont you worry at the end of this How To, you will have performed those steps. The easy way.
Without further delay, How To Unlock, Root and Flash A Custom Recovery On The Oneplus One
*This needed to complete the steps*

Step 1: Enable USB Debugging on Your Oneplus One
Before you can use any of the features of the Toolkit, First you need to enable Developer Options on the Oneplus One. Goto Settings > About Phone > Click Build number 7 times. Go back out then in settings you’ll see a new option labeled “Developer Options” Then make sure there is a check mark next to USB Debugging on the phone.
Step 2: Install the Toolkit
Download Bacon Toolkit from the above link, then run it and let it install files that it needs to root your device.
Once the drivers are installed, plug in the Oneplus One and have the toolkit Auto Detect which ROM your phone is currently running.

Step 3: Unlock the Bootloader
If you have a completely stock Oneplus One, the first thing you are going to want to do is to unlock the bootloader through the “Unlock” option, which will allow you to flash a custom recovery and ROMs.
To do so, with the Oneplus one connected just click on Unlock (now remember, unlocking the bootloader will wipe your one plus one so make sure you performed a backup prior)
Step 4: Root
Before going all clicking crazy. Go back into your phone settings a re enable again USB Debugging. If you want to install a custom recovery make sure the box underneath the root button is checked. Once you did that now click on “Root” and sit back and relax while the program roots the phone.

As you notice after your phone rebooted now you have a program named SuperSU.
Open it and let it update Binary. After thats done, you have unlocked your bootloader, rooted your device and flashed a custom recovery! The Easy way!
Now you truely have a 2014 Flagship Killer! The Infamous Oneplus One!
Enjoy.