580b steering valve seals leaking

Hi i am helping a neighbor with his newly bought 580b and we have been repairing a lot of things including oil leaks and were finally to the last big one that is the steering valve. It is leaking oil around the shaft that the steering wheel bolts to (top of valve) and im not finding a lot of info about it im sure it is a bad seal. I would like to tackle this myself rather than remove valve and take it in to a shop but im not sure if this is something that can be removed by removing the steering wheel and leaving the valve mounted in the column. I have seen on this forum someone wh has done a 580d but i have no idea if it is the same as the b or not. Any help would be greatly appreciated thanks

580b steering valve seals leaking