Kerry, I'm not sure that your set up is the same as in my 84 300DT but if it is, you can remove and replace the IP Shut Off valve without removing the oil filter housing. Ensure that you have the BOSCH OEM brand (definitely not that cheap and don't last RONAK brand ).

I found the DIY procedure and related warnings (scary runaway engine) in this FORUM by doing a "SHUT OFF VALVE" search. Very helpful.