Convincing them to do so should not be hard. Studies have shown that doctors are saving money for themselves and for their patients by using e-prescribing. They are ordering more low cost and generic drugs this way.
If cost saving isn't enough of a motivator, there are other very good reasons to switch to e-prescribing. Doctors and pharmacists can get the latest information and updates about drugs. They can also compare costs, something nearly impossible doing things the "old" way.