Or, if you're bloodyminded and persistent, once you've got it de-laced, you can whump and thump that tacoed rim back into shape, more or less, but it'll never be perfect. I had great fun one night doing this to a badly warped Rigida Blue label. Hammers, 2x4's plywood shims of various thickness, a trash can, my knee; the kitchen sink. I learned a lot, and ended up with a usable rim. The funny thing is, it's only about 2-3mm out of true now, but I can't get it quite that round, which I thought was going to be the easy part. Admittedly, I have very limited experience in wheel building.