Improving Equipment
Source Player Core pg. 236
A character who is trained or better in Crafting can improve an item using the original item and UPBs as raw materials using the same process as the Craft activity, except as noted here. The original item provides raw materials equal to its price. The DC of the Crafting check to improve an item is determined by the item level of the finished product. You do not need the formula to improve an item, as the instructions can be found readily available on any infosphere and are usually provided as a complimentary file when you purchase the equipment, but Crafting without a formula means you will have to provide raw materials equal to the item's price. It only takes 1 day to improve an item by spending the remaining portion of its Price in materials.
If you have the formula for the item you can improve an item by supplying UPB equal to half the difference between the two items, but you must work multiple days to reduce the materials needed to complete the item as usual with the Craft activity. You cannot improve an item to a higher-grade version if you're not capable of Crafting items of that level.
If you have the formula for the item you can improve an item by supplying UPB equal to half the difference between the two items, but you must work multiple days to reduce the materials needed to complete the item as usual with the Craft activity. You cannot improve an item to a higher-grade version if you're not capable of Crafting items of that level.