 Pull them off and either get a new spring or have them re-arched. The problem with the new spring is it may be exactly the same as your old spring, so you might just have better luck. If you get a good company that can do that, you might even contact a local spring shop. There's spring shops all over the place for trucks, and they would know where it could be sent to, or they may even do it locally depending on where you're at.