I was able to find the correct harnesses on eBay which was the most difficult part. I followed a step by step instructions someone on this site posted, but really it was just plug in the harnesses. I only had to splice in the nema 0183 wires from my older gps. The set up menu needs to be configured but the manual is available online. The panel needs to be cut out but I am lucky to be able to have a machinist open it up for me. It could be cut carefully at home if needed.How difficult was the upgrade to vv1.5?