I did them, i have EU citizenship, naples is most time/costeffective.
Basically, training as required for each license and then a test. The CPL is a little different. You need to pass the ATPL writtens, in 14 subjects. Its a substantial course and it would be the first thing i would get over with. The rest should be quite simple. As an american you would probably be interested in a distance learning course. Naples is not the best, but it is the cheapest option, And i will suffice. Set aside 6-12 months for the writtens depending on your present knowledge base and work situation.
Oxford and bristol in the uk are allso providing DL-courses but you would have to go to the UK to sit the tests and do the brush up.
have fun!