I believe the Yowii modchip is the easiest mod chip to install.
The Yowii chip offers the flexibility of multiple install options:
* Internal Quicksolder
* Internal Wire install
* External Wire install
The Yowii.net website has great tutorials on how to disassemble the wii and how to install using any of the 3 options above. Plus there is lots more information and downloads available on their website.
http://www.yowii.net
http://www.techsick.com/
http://digg.com/nintendo_wii/Buy_Nin...i_Modchip_here
http://digg.com/nintendo_wii/Best_Wii_Modchip