Thanks, Johnny! I couldn't find the plans. But, I knew they were here.
The great thing about Johnny's plans, is that the whole thing can be done with lumber and, like he said, a hammer and skil-saw. The bad thing about the hoop house is that it involves long lengths of steel tubing, which can be a problem getting transported.
If you're willing to tear down and transport, it seems that it might be easier to just build. Plus, you never know what you're getting into, when you offer to tear down. It could be a great deal, or... this:
I needed a satellite dish (one of the big 10 foot ones) for a ham radio project I was working on. I put an ad on Craigslist offering to remove one from someone that didn't want it anymore. So, I found the perfect one... and they wanted a "perfect" removal job. That sucker was 3 foot deep in the hard texas clay and, after almost yanking the rear end out from under my van, I finally convinced them that the best I could do was to cut it off flush with the ground and haul it out. It took an extra trip back, to pick up a cutting torch at my shop.
Another friend had heard that I was looking for a quonset hut to use as a barn on our ranch. So, they told us that we could have one for free, just for hauling it off. THIS TIME (after my experience with the satellite dish), we went to look at it, before we committed to the project. That sucker was 36 feet wide and 80 feet deep. It was two stories tall and had the framing for a house built inside it. To top it all off, the ends of the arch were set in cement and it was seamless, meaning that I would've had to cut it up with a cutting torch. It would also mean that I would've had to rent a crane to load an 18 wheeler about 20 times, with an oversize load, and reassemble the monstrosity at our ranch, rewelding every piece. I'm so happy that I declined the offer.
In all, I recommend that if you offer to disassemble and cart it off, be sure to look at it, first.