You are in luck. I just installed a ARB winch bumper on my new '13 JK and faced the same challenge. Fo a temporary fix, removed the unit from the frame bracket and just pried up the first arm. This allowed clearance and preliminary installation of the bumper. I used the back bracket arm to swing the unit back far enough to clear the 9k winch, then used a very heavy duty tie wrap to secure the buster unit, while still using the back mount bolt as the anchor point. This is only a temp fit, and was planning to fabricate an alternative after returning from our family Xmas trip.
With a little research I found a alternative at Rough Country. Here is the Rough Country solution to the problem and installation guide.