My back and arms hurt, but it was worth it!
Now, I can switch out my old box spring for my son's newer one, and I can use his headboard on my bed, too. The old bed frame is going to the trash, and we just took the top shelf of my son's old computer desk, and moved it under the loft. He has space for his computer, and a desk for doing his homework.
Tomorrow night, we will finish figuring out where everything is going to go.