If your shop is part of a building already, go to edit on that building and select the shop, click move, and then done. Now you hover over the building you want to add it to (make sure add to building is checked in options) and you should see a hint that says "add to building XXX" You click, and you should be able to move it to the desired location.
If the shop is not part of a building, just selected it click move and do as above to add it to a building.
Hope that helps.