Doors and Windows - Sealing an exterior door permanently

We just bought our first home! It's a 1950's brick ranch. Our problem is the house has too many exterior doors! 1 leads into the living room, but 2 lead into bedrooms. I'd like to seal off one of the bedroom doors and possibly turn it into another window. I'm not sure how to go about doing this or if this is a professional's job. Here's a breakdown of the door. It's about 5 steps or .5 stories high, and the exterior wall is brick. Has anyone else done this before?

You could replace the doors with windows by simply framing the bottom of the opening. Matching the brickwork takes a really good mason, however.