Hello, I'm rather new, but I've done a few lens jobs.
If you DO clean the lens yourself, you want to take every effort to document the way and order in which the lens comes apart so you can reverse the steps when it comes time to put it all back. I use small parts organizers to keep track of what parts come out during each 'step' in disassembly. If you have a digital camera...use good lighting and photo every step. Trust me on this...be as explicit as possible during disassembly so assembly is easy. What the others said about a spanner is good. If you can't get a hold of a spanner that works, modify some cheap pliers. Grind or use heat and hammer to flatten the jaws. Don't try to pull a cheap MacGuyver here, one slip and you risk destroying the glass.
For the actual cleaning, spit works. The enzymes break down the majority of mold/fungus without harming the myriad of coatings found on lenses. THEN....set all the parts that showed signs of fungus in a sunny window for a week at least. You may think you got it all with the spit/cleaner...but trust me, there is a good chance spores are still lurking, waiting to breed more evil balls of filth after you put it ALL back together.
Last of all.... google google GOOGLE! There are tons of people out there doing their own CLAs and you may get lucky. Someone may have posted a CLA for your exact lens. You can learn from their success or failure.
One bonus of having a pro do it is you generally get some sort of guarantee. However...do it yourself and you gain much more in the long-run.