Hello, I am planning on changing the oil pump on my GF's 2011 A4 when I get the new pump in. Curious if anyone would be able to direct me to a helpful how-to, or just give some quick tips on how to remove-reinstall the pump? Got the pan off and all that good stuff, basically just need to know how to take tension off the chain to remove pump. Can that be done from underneath the car, or is it easier from the top? Thanks in advance!