GreyQ,
The light on my 66-16 has three steel snap rings you need to remove. One near where the cord comes out and two in the middle which also holds the spring clip for the glass light lens. Once those are off it should come apart.
As long as the cord wires are good and the bare wires are only at the ends tape won't hurt at all.
Sew-Classics light {
http://www.shop.sew-classic.com/Ligh...k-SCE504EZ.htm } is the one to use if you don't want to rewire your OEM light.
Joe