I am not sure I understand your question FBW, but the conversion process includes a written exam based on the Bahrain AIP (open book). It is very straight forward after a few hours of looking at the manual and familiarizing yourself where you can find the information. Then of course, your simulator proficiency check for your aircraft must be passed before they issue you the Bahraini Licence.
A few years ago Gulf Air jumped through this process when it changed regulators from DGCAM Oman to CAA Bahrain. Aircraft registrations had to be changed, and it was without a doubt the largest personnel licencing effort the regulator went through in a short period of time. Looking at it as a spectator, I thought the CAA took a very pragmatic and pro-business approach to the whole exercise.
As far as the medical, I agree with Duh that it takes much of it's inspiration from the FAA medical (even the certificate you walk out with is similar in format), with the exception of that they don't ask whether you have a prior DUI conviction. A very straight-forward process. The only difference is that they do some kind of a blood test (it ain't for HIV, or Cholesterol . . . I don't understand what it is for) but that might be my physician's thing. They don't shove a finger in your backside either.
Class 1 medical (required for ATP and Comm) is valid for 12 months to age 60, then it goes to 6 months.