You can get the latest file release from here:
www.sourceforge.net/projects/wgois . Or, using that same location, get directions for CVS. I recommend TortoiseCVS, it makes tihngs fairly simple. Install Tortoise, right click on your desktop or folder, and click on download CVS. Than, use the CVS location as specified on the source forge project page's CVS link.
Then, you have to set the OISConfig.h define for Wiimote to uncommented. Grab some HID.h / HID.lib stuff from a forum post here (or off the net). Then simply build the project.
Hope that helps.