Just changed my yesteday its right under the left hand side back (back) corner ( behind fan approx ), make sure you have a 90 degree mini screw driver the back screw is a PAIN!!! to get out. Takes time but worth it in the end.. just 2 screws and its out.
I only had flat out (number 4) work on mine but have 22.214.171.124 working a treat!!