As I use MPW, I’m kind of going on memory from a friends system with CW. Putting the SDK into the “MacOS Support” folder inside the “Metrowerks Codewarrior” folder will add all the gl headers to the system search paths so you’ll have access to all the routine names. You’ll also have to manually add the stub libraries to your project though or you’ll get link errors, and the GLUT/TK/AUX/MUI libs as well as their respective resources for those libraries to work.
The other way to do it is to go into your project preferences and add the header search paths (whereever the sdk is located) to your project, and then add the stub libraries/libraries/resources to the project as noted above. But as you’ll have to redo this for every project, I think the first way is the way to go.
I hope this helps, and that my memory hasn’t failed me.