As already mentioned before, you need to pass the respective knowledge exams and check-rides (PPL, IFR, CPL). But may I ask, if you hold an EASA (frozen) ATPL why do you want to get an FAA TR? The majority of the airlines/operators require you to have some time on Type, usually around 500 hr. Assuming you're a Non-US-Citzen (meaning without the legal right to live and work in the States) no US airline/operator will hire you. So what's the use of an FAA TR, since it can't be transfered on your EASA license. As an EU-Citizen I'd be looking into the so called "Line-Training" where you get your TR and basically pay to fly as an FO for a certain amount of hours.