How to remove a guillotine valve

I have a guillotine valve that won't come out. It's a 2003 700 classic touring Polaris. It move some about 1/4 of an inch and then brings up. I've used carbon combustion cleaner to no avail. I need to replace it which is no big deal as I damaged this one so far. Just wondering on how to get it out....thanks

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How to remove a guillotine valve