How to Replace Alternator Ground Screw

While reading another post regarding "Pulsating headlights and Dome Lights". My van is expierencing the same issue and altanator test shows good voltage drop. It was mentioned that TSB 01-06-03-005 could be a good try to remedy this problem. This is to replace the ground screw of the alternator.

I got the Ground Screw from GM dealer (Part of it called Fastener "Kit" Cost $3.15), I just need some help that how to reach the alternator and replace this philips screw with washer.

Any help will be great.

Thanks.