Upgrading a CJ PV-10A

I would like to know if there are any suggestions on what can be done to improve this unit from stock by replacing caps, capacitors etc. Anyone done this? What parts did you use or do you have any recommendations? I am not a techie, nor can I handle a soldering iron but I have an electrical eng. friend who loves doing this kind of stuff, so what I really need is a parts list and where to purchase.