I believe its in the same place as on the XJ. The location is on the right hand side of the gearbox near to where it bolts to the engine. Before you attempt to remove the NSS there is a 10mm bolt that can be losened to allow the NSS to adjusted. Losen this bolt/nut and rotate the switch clockwise. Tighten then try to start and see if there is any difference. Removal is relatively simple but dont rush it as theses have a weak plastic body which will break easily. The instructions for removal are pretty basic, havea search on google
Posted from my phone as its quicker than the pc connection