Pipe wrench.

From experience--if the pipe on which the spout is mounted is galvanized iron, it should come off. The spout will be useless, but it should come off. There is a chance the iron pipe will unscrew from the fitting in the wall. That is not a problem, as you can buy another piece of pipe and replace it by simply screwing it into the fitting(with appropriate sealant.)

If the pipe is copper, there is a chance the copper pipe can be damaged. That means removing/repairing the copper pipe, which can be difficult.