Previous searches: American accent, learning American accent, wikipedia and linguistic sites
I am not a linguist, so a lot of my searches are frustrating because I can't read the phonetic notation and none of the learning sites are providing me with what I want to know. Most of it's people pleading for help and not stating their specific problems. I've got a British man (technically Irish, but he's passing himself off as British with that stiff-upper lip accent I've read is called Received Pronunciation) who needs to disappear into the population pretty quickly.
What I want to know is, given his current accent, how hard would it be for him to counterfeit a standard American accent? On that note, what would be particular problem areas, or specific parts of the accent that would be harder to pick up, and thus might give him away? I'm thinking along the lines of that that generalized upper Great Plains, sort-you-hear-on-tv accent. Also, due to the nature of the situation, he has no voice coach or anything of that nature, so really he's just winging it. Where might he quietly find information on learning the accent without outside help, assuming he has some prodigious resources to work with? I'm useless on this topic, because I happen to speak in the generic accent which is so desirable, and don't know what the sticky spots could be.
Thanks in advance!