The instrument cluster is out. Your suggestion was a winner!
Removing the speaker grill and the left vent and pushing from the back is a great way to get the instrument cluster out. It was much better than trying to pull from the front.
To my pleasant surprise, I found only four plugs on the back of my instrument cluster--and no speedometer cable (I should have realized that it's a digital speedo and wouldn't have wasted time looking for a speedo cable).
I've learned that I have to take these postings with tongue in cheek--as my experience removing the instrument cluster was quite different from what others have reported in this forum. There was no need to take up the carpet, there was no speedometer cable.
Also I did not find the soldered-in light bulbs (outside temperature and odometer lights) that others have mentioned. Happily, mine were the twist-out light bulbs.