Well the epoxy will take several day to harden, so that would probably be around 4 days. After that you'll have to remove all the remaining epoxy around the dice until there is a thin layer left before you hit the dice. With a sanding machine that would take about 10 to 15 minutes, by hand quite a lot more. After that it would be a couple hours of sanding to go through the different grits, polishing won't take to long. So in total you can get all the sanding and polishing done in one day if you are handy but you'll have to wait until the epoxy hardens.