Offroad-Express

Hey guys, just a quick question here. I am looking at a land cruiser at the moment and he says the diesel pump needs rekiting. I was wondering on the 81 3b turbo land cruiser how hard this is to do myself and how much parts are approx. Or how much is would cost to get done in the shop??

Thanks for your help

He says the pump is leaking oil on cold start for about 40 seconds