Holding Tank Replacement on an IP45

Hello,
We are new owners of a 1996 IP45.  Trying to confirm if the new holding tank installation will require removing the cabin sole or can it be installed by creating access under the starboard side bunk.  Previous owner had the old tank removed without cutting through cabin sole and did it by creating access under the bunk.   They may have cut the old tank out to remove.  My guess is other IPs of similar size would have the same holding tank design location and issue.  New tank is on order from Dura Weld.  Thanks for that referral advice on tank supplier from this forum.  They had the plans for the old tank on file and were very helpful.
Thank you,
Barry

I just finished replacing the holding tank in our IP350. Yes, removing the old tank would have required pulling up the sole. I chose a totally different installation and left the old tank in place, filling it with expanding foam. I installed a new custom tank behind the toilet, removing a portion of the shelf below the sliding cabinet. I just put together a slideshow/film that you can see at: photos.app.goo.gl/LF9GJ8vC8cDPCDVFA