I pulled mine out when rebuilding. Those rear ones are a bear to get to to remove. Not a job for folks that are not somewhat fit. When reinstalling I trimmed each air line 1/4” or so they have a fresh hose to seal with the fitting. One other thing, I have to resurface the face on my manifold by lightly milling them as there was a good amount of corrosion and I was afraid that some prongs may not get a proper seal.
Richard,
If you’re going to rebuild the spare one on the bench then swap, why not just remove yours, rebuild and reinstall?
Best of luck with it. Not a fun job.