I'd also like to point out that, if you're swapping a Lite board for a premium board, you're going to have to swap power packs as well. Lite board uses 4 AAA batteries, where the premium boards use the 14500 batteries
Yeah, basically just swapping the whole pack would have been easiest. It would have just required snipping, stripping and soldering wires. But, as I said, you can't guarantee that they used the same colors of wires, so some extra steps may have been necessary. It's not terribly difficult, but also not something I'd suggest as a first saber project.