How to reset ECU and eingen system - 1996 Land Rover Range Rover

I'm not aware of any reset that can be done without the Rover TextBook. If you simply want to clear the stored data, trouble codes, etc thats pretty simple. -engine off, remove negative lead from the battery (single black cable). I usually wrap this with a rubber glove or a rubber drawer toolbox liner, something rubber any way just to be on the safe side and then tuck somewhere out of the way so it doesn't springback and make unwanted contact with anything. Once your negative lead is removed many stored items will be cleared from memory. Let Rover sit with cable off for an hour or so. This will also discharge the stored power within the BECM and the ECM (Rovers brain). At this point everything that can be cleared in your garage has been cleared. There are a couple systems that I believe are not affected such as ABS and the EAS system. If you are having airshock issues this will not reset the EAS faults. Hope this helps.