If it were me, first of all, I would take several cuttings for clones so as not to lose the plant/strain entirely if something goes wrong, you'll still have clones for next year.
Then, I would carefully start digging in a circle, starting about 12 inches from the longest branches of the plant, and work your way around the plant, trying to get as close to the root ball without cutting roots (although you will inevitably cut into some in the process) and once you have it all loose from the ground, carefully place it into a suitable pot that's at least as wide and deep as the root ball. Fill with soil, water it in, and do your move.
Try to think like a paleontologist, excavating as carefully as you can without destroying what you're digging up. It doesn't look like they're flowering yet, so that will make life easier. Don't be surprised if the shock of transplant does start the flowering process, though, as that's most likely going to be the outcome. It can go either way, it may delay flowering or speed up flowering, but as someone said above, it will shock the plant no matter how carefully you do it, so just be prepared for that.
