This is a very common task that I should charge to teach but I believe in giving back to the community so I'll be working on extra operation classes like this head and set and mounting fabrication from seat to prong by prong. Here the original setting was composed of only two prongs, the customer lost the cz stone about .40ct, so I decided to do 3 prongs with a .50ct cz. Unfortunately I wasn't able to catch the final result, but the customer loves it. At a jewelry store where they sell loose stones then they offer this service to set their stone in your mounting and that's where you come in and make that happen either by ordering a new head or mounting or my personal favorite is to add new prongs around the same setting.