Ultrafire 3t6 upgrade. Pointers please.

Hi have an old ultrafire 3t6.
Switch hado melted. I can source a switch but can anyone recommend a replacement upgrade driver?
It’s a 26mm YD032-26.
If it’s viable and cost effective I may go a little crazy with it if the parts are available. Seems as the xml u2 emitters are ok. Not sure they would survive 3a each? They look identical to a laticcebright.Any constructive pointers would be appreciated.
There’s got to be a build thread somewhere.