Step 2. If you do insist on taking the couch up the stairs, bungee it closed first so that when it gets stuck, you have a chance of getting it back down again.
Step 3. It's not so much that the metal frame comes off the couch as that the couch comes off the metal frame. Our couch had two load-bearing screws and three retaining screws on each side. The retaining screws were most easily removed, and the load-bearing screws loosened, while the bed was open. With the bed closed again, the frame slips off the load-bearing screws and drops down an inch or two to rest on the ground. Then the upholstered part of the couch comes off and can be levered with push-brooms over the second-floor porch railing. The metal frame is enough smaller than the overall couch to make it up the stairs.
Step 4. Make sure you have someone to dedicate to the job of laughing as the couch is hoisted over the porch railing.
Step 5. Don't call all of your friends to help you move the couch. That way you have someone fresh to call to bail you out when your initial attempts fail.
Step 6. Make sure you know someone with a complete collection of screwdriver bits, so they can bring over the collection and provide a number 2 Robertson (square) bit, when all you have is a number 1. This also provides some extra amusement for the dedicated laughers for when the couch isn't actually being hoisted.