I cut out a section of the leading edge from top to bottom, as cleanly as possible, back to the spar. With the plane upside down, I also cut out a section on the bottom, behind the spar, large enough to allow me to work. I made all these cuts as cleanly as possible. If I were doing it today, I would use one of those multi tools with the oscillating blade.
Sand down the area of your cut line, before cutting. You will need to have this area sanded when you put the pieces back in and this makes it a lot easier. Yes, I used the Large area washers. Why not. Congratulations on making a wise decision. See N64KR at <http://krbuilder.org/> http://KRBuilder.org - Then click on the pics 2016 KR Gathering - Mt. Vernon, Ill. Peoples Choice at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best KR at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Paint at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Firwwall Forward at 2013 - KR Gathering in Mt. Vernon, Il - MVN Best Interior and Panel at 2008 - KR Gathering in Mt. Vernon, Il - MVN Daniel R. Heath - Lexington, SC