Spool Valve Assembly Problem

[Wayne]

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Problem:
One of my needle valves on the Spool Valve Assembly is not allowing movement (I can't get it to go in when pushed): it's in a locked state.

Has anyone ever had this issue?
Has anyone ever changed their Spool Valve Assembly?
How difficult is it to work on the Spool Valve Assembly?

If you have experience with this, please advise how to proceed.

Thanks - Before I get started