Anyone ever service their own a/c?

[pexcellence]

Has anyone service their own A/C? I am the third owner of an 86 420sel. It looks like this car had A/C service three times in the last two years (as recently last year). Now it is not cold again. There must be a leak somewhere. I look at the hoses of the A/C system and saw that the ones from the drier to the condenser and the condenser to the compressor having gunk on them. I think this is the source of the leak. It there a good source to learn to diy or should I keep paying the mechanic to fix this? Is there a lot of equipment to buy? I am fairly technically competent and can learn very quickly.

Thanks,

John