This bolt is so rusted I'll have to hacksaw it off.
Cut the rest of the thread away which will require a hacksaw and vise.
This will entail unscrewing the assembly and may require a hacksaw to get the rails off.
Before take off from England I'd hammered those pins in so tight that it would have taken a hacksaw to get them out.
The junior hacksaw is a small saw, which is most suited to clean cutting on very small sections.
Either undo the supply pipe connections at the base of the tap or cut the pipe with a small hacksaw.