You can't convert to FAA, but you can use the hours already flown towards the requirements, which is almost the same thing.
The requirements are in part 61.151 onwards (Google: 61.151) - with 14,000 hours he's likely to meet all the requirements, but they can be picky so he'll need to check how instrument time has been logged etc to be sure.
Basically he'll need to do an ATP-CTP course (7 days and $5,000) take the ATP written test (another weeks study) then a practical test in an aircraft or simulator, 777 being the obvious choice. In this climate I'd expect an airline to pay for all of that, and there will be airlines queuing round the block offer him a job