I have a 2005 Winnebage Adventurer with the HWH 325 leveling system. I have had a number of problems recently which has involved the shuttle valve and all 4 of the jack solenoid. Each of these valves has a seat assembly with an o-ring that can (and will) get stuck making the removal impossible due to the solenoid(s) getting hot. This happened to me and I wanted to share the tool I made to remove these seats with the forum.
You have to be willing to scrap one of your non servicale valves as they are rebuildable by HWH. Grind the OD threads off of the housing and the attached pictures. You can now screw this housing to the seat only. This allows you to jiggle the seat only and/or pry between the housing and the manifold without fear of hurting other parts.
HWH will tell you that you can screw the old solenoid in 3 or so turn and do the same but you can't do that if the o-ring on the seat is really stuck. If you pry on the solenoid with the OD and ID threads engaged, serious damage can happen to the manifold.