It should be dead easy.
Steampunk gadgets are items of power. That covers them.
The big robot dudes are just built like normal beasties. Just decide on Refresh and such.
Alchemy is, well, alchemy. It's covered already in the rules.
Races need appropriate High Concept Aspects and, where necessary, powers.
Your only real decision is whether you want to keep the whole Refresh = choice bit. You can keep that as is, and you'll get similar stories where powerful beings are ruled over by their nature.
Or you can get rid of that. Give characters a set Refresh that doesn't get used for powers and Stunts, probably somewhere around 5. This doesn't change. Then give them separate points that must be spent on Stunts and powers; anyone who doesn't take supernatural powers gets 2 more points to this second pool. Failure to spend your second pool basically means that you have points floating around that you can't use for anything; you might be saving these for more expensive powers.
Oh, and you need to change a couple of skills. That should be pretty easy. Guns becomes Archery, etc.