Surface light: unscrewed the single screw holding the glass plate over the bulbs under the microwave, replaced bulb.
Interior light: took off top grate (two screws holding in place), removed metal plate, changed bulb, replaced all.
Note: These were the same bulbs for both locations. I only ordered ONE from AppliancePartPros.com, and got another one at a different store-- 40Watt Appliance Bulb did the trick (slightly different bulb shape, but same base).
UNPLUGGED MICROWAVE BEFORE DOING ANY MAINTENANCE!