Instructions for the medical exam to be scheduled with an appointed location for both medical and eye exam should be follow in a message on your DS status page. You do not choose your doctor for either of these exams. Exams are contracted and the connection is through DODMERB instructions. After the exam, the physician uploads his findings.
Found this slide presentation that looks like a nice step by step.
DoDMERB PROCESS USER ID IS YOUR SSAN ( ) PASSWORD IS YOUR FULL LAST NAME* *TYPE YOUR LAST NAME EXACTLY AS IT APPEARS ON THE DETACHMENT ROSTER!
slideplayer.com