It can be done, but you really need some serious gear to pull it straight. Some shops offer a service like this, i think they use a large hydraulic press and bend it back to shape. Even if you cut the piece off the front, when you clamp a new one in it will still pull back to a bow, maybe not as much but it will still be there. You may be able to do it with bottle jacks, chain and a large I beam. hook chains around the I beam at each end and over the front of the bucket and use the bottle jacks to press the bottom of the bucket up.
