Well the carrier and mcpcb involves cutting traces (a dremel tool is good here) and soldering jumper wires. There are some pictures of how Lexel mods the mcpcb for 6v here. He said modding it for 9v is a bit less work.
The driver is pretty straight forward. Physically swap it out and resold the wires to the switch and mcpcb.
The hardest part is taking the light apart now that they started gluing them together. You would probably need a vice with some padding on the jaws and maybe some rubber strap wrenches. I think Lexel has some wooden clamps that are cut to fit around the bezel and some threaded rods to clamp around it nice and tight in order to break it loose. Since you already have your light you can try and see if you can get it apart and if so, you could probably do the rest of the work yourself.
Ps, spring bypasses are not that hard. You just want to add a short length of wire to the base and the very top of the spring so that it’s still capable of compressing down.