No way around it, the stacked valves are a pain to work on. When I do my 450LP o-rings I will be changing every single one in there, all at the same time. Must be near 50 o-rings between the valves, pipes and relief/regulator. When I did my 450 gas, I stupidly used a slightly undersized o-ring in the last valve. That started leaking pretty so quick. Don't forget the o-rings and clips for the steering priority valve plugs. Those seem to blow out at the worst time. The IPLs will have the oring dash numbers so you can have them on hand.