Sounds good. One point--removing the UGF will create a bit of a cloud, but nothing serious. Don't pull all the gravel out, just remove the lift tubes, hook the filter with a finger, and ease it out--it's not totally easy, but it can work. I wouldn't pull out the fish for this, just remove the decorations. Then plan on rinsing the filter media a few extra times for anything that is released. The other accumulated debris will be the foundation for mulm that the plants will use.
I pulled out a UGF this way from my 40, and there was a bit of clouding, but it was cleared within 24 hours, no spikes.
I pulled out a UGF this way from my 40, and there was a bit of clouding, but it was cleared within 24 hours, no spikes.