Good tips already given. By all means go ahead with the repair.
But keep a good eye on your clutches. I see from your profile that your boat is 1984 built. I've got the same clutches on my 1980 Hunter. A little older. (A double on the port side and a single on the starboard.) I had to replace one a few years ago because a side plate, in the spot just above where your stubborn pin is stuck, had developed a stress crack and then broke clean off. The pin no longer had a firm fulcrum point. The plastic had reached the end of its life. Became brittle with age and sun. The other two spinlock clutches I fear aren't far behind. In fact just yesterday I noticed a stress crack on one in the same side plate spot as the failed one a few years ago. I recently found a couple of "pre-used" Lewmar aluminum double clutches in good condition. Next month I will be removing all hardware to do a cabin top repaint. I will fill/fair the Spinlock clutch holes before the painting. Then replace them with the Lewmar ones. I am the type that will try to repair anything. The old Spinlock's though have just worn out on my boat.