An easy way to measure the distance between your pupils is to stare straight ahead while wearing a pair of glasses and then have someone put a dot with a DRY ERASE marker right in the center of your pupil. That way you can measure and remeasure easily
As for the other measurements, if you have a pair of well fitting glasses that you bought in an optical shop they should probably have your measurements printed somewhere on the inside of the earpiece. It's worth a look anyway
Now you have me in the mood to buy a new pair!