Double check the advice Phoenix gave to “westcoaster”, which may give you ideas about how to open with a seam ripper if you chose, although westcoaster found a faster method 
and make sure to go slow and document the layers and order they’re in. Pictures are wonderful. It looks like you’re set to go.
Hi Annmarie,
Thanks for the pictures 
Your plan is a good one except as dn mentioned I would personally use a seam ripper to remove the tape edge because it can save the top quilted cover if you want to use it for the mattress or something else and you don’t need to rip any fabric (which can prevent fraying edges if you plan to keep the cover). It can go quite quickly once you get it started and just push the seam ripper along in longer “strokes” as you hold out the tape with some tension.
Phoenix
Hi Annmarie,
It’s nice to see that my mattress surgery photos are getting put to good use
I agree with Phoenix’s advice of using a seam ripper. It is definitely cleaner and will allow you to reuse the top. FYI, I also started out using a seam ripper but once I exposed enough of the quilting layer, I quickly decided that I was not going to be reusing the top. There was 2.25 inches of cheap 1.5lb density foam quilted to the top and I didn’t want to go through the trouble of removing it. This is when I opted for the utility knife.
Good luck with the surgery!
westcoaster
Thanks westcoaster I’ll keep that in mind while I gather up the nerve to cut this thing, in the mean time (don’t laugh) hubby took some sheet styrofoam we had in the cellar from some project, wrapped it in a light blanket, put in on top of his side of the mattress, placed both of the 1.5 in memory foam on top and is sleeping fine. I wanted to ask you about the latex toppers you used. I want to get a firm one for his side after the surgery but considering he is sleeping on a piece of styrofoam and last week was sleeping on the hard side of a one sided mattress, I’m thinking maybe extra firm for him with some memory foam from the dissection on top. Did you reuse any of the material you took out of the mattress topper?
As a side note the Pure Latex Bliss nutrition model has a firm layer over soft
Hi Annmarie,
The only material I reused was the layer directly above the springs (5/8" of memory foam). The other polyfoam layers are sitting in storage just in case; but so far, I am pretty happy with just the latex topper.
westcoaster