I'm plumbing up my new brewing sculpture and I missed some of my angles connecting the pipes together. Does it work to apply a little heat and just twist the elbow?
If you are heating joints that have already been soldered you will want to apply more flux to the joint (without taking the joint apart) after you've heated and turned it. Then reheat and flow more solder into the joint. It is going to be hard to not scorch the joint and it will not look pretty but you can get it to hold with this method. I'd really consider just replacing the mistake.