You can get a validation of your FAA license that's valid for 3 months IIRC. You can get one more validation extension before you'll need to convert your license.
Conversion is pretty much a non-event.
You'll need a verification letter from the FAA that you can get on their website outlining your license, type ratings, medical, etc.
You'll need your training file from your most recent training event - initial or recurrent. Make sure they're stamped. Usually, your employer will deal with the paperwork and you'll have to fill out some info, but that's about it.
You'll need to take a GCAA class 1 physical. Your employer will pay or reimburse you for it.
Finally, you'll need to take the Air Law Exam. It's a very straightforward 100 question multiple choice exam. Some prep and you'll be done with it in 15-20 mins.
Your employer should pay for all this and within 2-3 weeks if they do the fast track option, you'll have your UAE GCAA license.
The above is how bizjet operators do it. The local airlines usually don't even deal with validations, and your last training event will be done by them.
A fairly straightforward process.