Raw water wash down ball valve replacement

[dadsdayoff2]

Last season while wiping out my bilge, I realized I have never touched the ball valve that supplies my raw water wash down pump. So with some effort I closed it and reopened it, or so I thought? Since then the presure has dropped to half of what it was. So I have to assume the valve did not open back up all the way and now needs replacing. Has anyone done this job? Can I replace the ball valve w/out replacing/messing with the through hull pick-up? Thanks for any input!