I did mine about 8 years ago and it took me 5 days in an A&P school in Dallas, Texas (Not ACME, the school I went to was quite small and
AFAIK the owner closed it a few years ago after he retired). The reason was that I was (already a B1 at the time) working for a company, which had a maintenance contract for an American airline.
If you are not an American citizen or resident in the US, the biggest obstacle will be to provide a letter stating that you, as a foreigner, require an FAA licence to service N-registered aircraft. This letter has to come from the operator or the maintenance company and it is even better if it states that there is no American citizen available to do the job. Fortunately I got one from the wellknown American freight airline, which was accepted by the FAA field rep during the preliminary interview (which was also used to check my ability to speak, read and write English).