Very simple to do. Best thing is to lift the couch to expose the original battery box. it is a simple matter of duplicating the installation of that one. I have done it on my 1985 Sovereign
a couple of years ago. Worst part is carefully cutting the hole in the skin. Measure and measure again before the cutting. Use stainless steel screws. The screws have a tendency to loosen over time and need to be tightened periodically.