I have a complete set of tools, and will dissamble the consumer grade lenses to clean them. usually, its just a 10 minute job. However, I've never seen any need to clean my "L" lenses, not even my 3 year old 17-55mm EF-s. Most of the dust I find is behind the front element which is normally quick and easy to remove and clean. I've also cleaned oil off the aperture of a older manual aperture type lens (only one). That worked out well.
Microtools.com sells a lot of good quality camera repair tools, just a couple of cleanings pays for them. I've always been one to take things apart and repair them, its kinda fun. I first bought a canon repair manual and then experimented with old Canon EF basket case lenses that had been totaled from being dropped. I found them at garage sales.
If it turned out to be a difficult cleaning job, I'd just send it to Canon if under warranty, or take it to a local repair company, there is one here in Spokane that I deal with. I do not do this for others, just myself.