gearbox oil?

is this easy to do? drain etc and what would you refill with is there diffrent types etc? would this be worth doing as well ? i have as much knowledge of this as a 5 year old lol just theres a small bobble keeps accumulating under gearbox but not a drip

theres a p38 guide on difflock.com or try rangerover.net

Easy to drain (sump plug) and filling depends whether you have a gearoil dip stick (if so you fill through there) or if not then there's a plug on the side you fill through and a procedure to follow (shifting through gears etc).

Have to be careful you don't over fill if you're filling through the dipstick and check level regularly.