Joe,
The sheets detail the interior mount. Overall it's very easy. Be sure to tape up and secure the un-used portion of the SPF original wiring. The most difficult part is bolting it in. One pair of arms are not long enough to hold the box, screw, nut, and wrench at the same time.
Also, to be safe, I put the 3000rpm module in first to check the rev limiter function. My Windsor spools up so quick it would be real easy to go way over redline if the rev limiter was not working.
You will also find that the MSD makes quiet a bit of noise, call it buzzing, totally normal.
Chuck
SPF1591