Start by rinsing under warm water to remove loose food. Don't soak as this will cause rust.
Use a chainmail scrubber or food scraper to remove stuck on food.
If there are rust stains remove with steel wool. We typically avoid steel wool because it can harm the seasoning but if you're re-seasonsing, it's fine.
After cleaning dry well and apply a very thin layer of oil to the pan. Wipe off any excess and put away.
Every so often you want to season the pan. To do this coat with a thin layer of oil. Too much can make it sticky.
Set oven anywhere from 350 - 500 degrees depending on the oil used, Place a sheet pan on bottom rack to catch drips.
Place cast iron pan upside down on rack and bake for 1 hour.
After an hour turn off oven and allow pan to cool with oven. Then put away.