In this Instructable, I'll walk you though my steps of completely re-working my Wii to fit inside an old-school NES case.
Several times in this Instructable, I'll be referencing the How-To: Make a Wii laptop
page by Benjamin Heckendorn (thanks!). He has some VERY good tips on complete Wii disassembly as well as de-soldering.
Here are the tools you'll need:
A Wii (duh!)
An original NES
Small Phillips screw driver
De-soldering braid or de-soldering iron
Hot glue gun
Dremmel tool or drill with a fine tip drill bit (1/16" and large drill bit (5/16")
Wire (preferably multiple colors, I used 18AWG, but probably should have gone thinner in retrospect)
SD Reader you don't mind destroying (or SD port ordered online)
2 momentary switches (preferably 'micro' switches)