Replacing an existing switch presents no problem at all, especially if using the same type, etc. Imo, a scale of an easy 2...
Note; make sure the tube to the switch is clean of any goop/crud.
Most Square D sfg2 switches are set at 20/40 or 30/50. So make sure you follow the instructions on raising the settings.
Also, make sure the pressure tank (when empty ) has air pressure set at 2 psi below the pump's cut-in setting.