Oilleak problem from hand brake drum cylinder

Hey guys, pls to meet you, i have just bought a land rover series ex millitary LWB series 3: I am noticing that a few oil is leaking from the hand brake drum, can someone tell me what is the problem pls? and, it is a big of problem to arrange the fault? Pls help 10x

Put into difflock
Chock wheels
Remove propshaft ( or drop front end)
Remove handbrake drum
Remove brake shoes and springs ( taking lots of pics to ensure yu put them back the same)
Remove handbrake link to rear backplate
Remove backplate
Remove adjuster
Wash everything in petrol to get rid of oil and allow to dry
Prise out old oil seal
Tap in new one using a big socket
Reassemble brake adjuster and repack with grease.
Reassemble.

Or

Follow Busters guide ( has pics)