Update PCB Without Capture Schematic?

I am in the process of learning ORCAD and need advice on how to best update a PCB. I am using ORCAD 16.5.

I am working on an old project and don't currently have all the files I need (I am hoping this will be corrected in the future). I have a previously designed PCB (.brd file) but no corresponding Capture schematic. The update I want to make is fairly simple (changing a resistor to a potentiometer). Is there a simple way to do this in PCB Editor? Or is creating a new schematic the best approach?