If you don't have the knowledge to take it apart and do the basics of drive cleaning/repair, I would suggest one of two things. You wouldn't be asking here if you already knew I would assume...
A: Find a slot loading drive of some sort that is of no use(Car stereo, PC drive that's slot loading, etc), and tear it apart to learn it's inner workings, and try to get it back together again.
Google information on this and the Wii's drive before actually touching the Wii itself, plenty documentation on it out there.
B: Send it to someone who can fix it.
The best way to learn something, is to tear it apart, but you're best off learning on something destined for the trash anyway, not your intended repair.
My bet is on the laser needing cleaned and/or adjusted, or replaced. Something that is trivial, once you can take the thing apart and put it back together the same as it was though.