Ohm my Golf..

So I've looked through the section of posts regarding engine swaps. Though the one that I found which was in closest regards to mine was someone droppikng in an ALH, whereas I'm dropping a BEW into a 03 1.8 gti. I was hoping that there would be some information available as how to go about dissecting/splicing the two wiring harnesses. If it's here could someone kindly direct me to said area, or assist with any information at all it would be really appreciated at this point. The gasser was my daily, and am needing my daily back with the heart of a diesel. Thanks in advance.