Hi, (I hope this is a genuine request!)
Unfortunately I do not own a 2002 Range Rover, however you could try this link or go to a local dealer and ask all your questions about a secondhand 2002 range Rover.
http://www.landrovermanuals.com/rangerover2000.html.
I purchased a disc from ebay, which I have just checked and the new Range Rover is mentioned.
To unlock -open the rear tailgate; "with all doors unlocked, press the switch on the bottom edge of the upper tailgate and lift to open". "If single point entry has been operated, and only the driver's door has been unlocked press the tailgate release button" (presumably on the dashboard). "With the upper tailgate open, press the release button on top of the lower tailgate, then lower the tailgate". There is also an emergency upper tailgate release if the battery has become discharged. This involves folding the rear load space cover and levering out a tab, this is then pulled and releases the upper tailgate.
Having skimmed over some of the manual on my CD, I stongly recommend that you visit ebay as the vehicle is complex and the manual suitably informative.
Regards
Andrew
Andrew