As said above...It is F*****G heavy. I have done it on both Disco and RRC and it is doable but getting back in in one piece on your own is like wrestling with a demented alligator.
Town and Country. Use them on the Disco , P38 and on the Horseboxes. Very good fit, very hard wearing and reasonably priced.
http://www.townandcountrycovers.com/vehicle-seat-covers/landrover.html
Used one back in the 1990 at Ford , seem to remember they were faily self explanitory, with all the leads cleary marked up, and scope programs push button. Try your local MOT station as they were MOT aproved and they might have an old manual, also try your Snap on dealer as they sold them back in the day.