I pretty much stay away from Pietta's now, but have done a couple. What you need is a heat source like a plumbers torch, propane or mapp gas will work fine. Some sand paper and a soup can with some oil in it and a magnet and your set.
Basicly you have to harden the steel, then temper back. Bring the sear up to temp where the magnet is no longer atracted to it and quench. Be carefull and don't over heat. Don't rely on heat colors as with differant lighting will give differant colors. I normaly darken the room to better see them, but I still check with a magnet. After quenching and it's cool to the touch you can bake it in the oven for an hour or so at aroun 400-450 deg. F., or simply sand the decarb off to bright steel and bring back up to temp slowly with the torch and get a nice even straw color, heat from the bottom and let the colors rise to the sear, then when it's straw colored dunk in water to stop the heat and keep from getting too soft on the sear. Weather you do this with an oven or with the torch do at least two tempers, three are better.
The magnet check while bringing up to criticle temp for the quench is a good all around road sign. Most steels the magnet will just start to stop sticking at about 50 deg. below where you want to be for the quench, over heating can cause large weak grain structure.
Best to practice on a piece of scrap high carbon steel first, or an old trigger to get the feel.
It's realy not that hard, just take your time and it'll come out fine.