Donkey tail needs repotting- how?

I have had this donkey tail for nearly a decade, and haven’t repotted it that entire time. I fertilize it with cactus fertilizer every couple years when I remember. Despite my lack of attention, it grows wildly, and even flowered this summer. The pot it is in is the stupidest shape, I was new to houseplants when I got this. It will not come out easily. If I try to dig it out of this pot (or smash it) the plant could take serious root damage, and it will likely lose a lot of delicate buds in the process. I’ve moved this plant like 4 times though, and once across provinces in a laundry hamper, so I know it is hardy- but I don’t want to hurt it more than I must. Do you think it’s ok if I just back fill the pot with fresh cactus soil? Or is it time I break the pot? I also plan to do a serious hair cut on it this summer, to basically take off the lower half of all the branches to make a second plant. Would it be ok if I dealt with the soil and cut it at the same time, or could that shock it too badly? Any advice would be appreciated.