I converted mine a couple years ago, took about 1.5 hours.
If you're somewhat mechanically inclined it'll be fairly simple.
The instructions aren't the greatest, so my advice is to read them, shake out the parts supplied, read them again and go step by step, slowly.
In the couple seasons since I converted mine, I've not had to go back and "refix" any of the mods made, I was a bit concerned over the throttle linkage not being right but it's all good.