They season just as any other carbon steel does. There are lots of right ways to do it, all of them about equal, and none involving potatoes. Don't make yourself nuts trying to find the one, best way. There isn't one.
At a microscopic level the surface of the pan isn't... completely level that is. It's got all sorts of little pits and valleys. Often they're compared to "pores," but I'm compelled to add by a careful poster that they are not actually pores, and the pan is not nor was it ever actually alive. At any rate, if the pits are filled with oil, and the impurities are cooked off, the "pores" are filled with pure carbon up to the level of the pan's surface. The carbon is very tough, and very slippery. Thus, the nearly-non-stick surface is born.
To make it happen, either pour either a little or a fair bit of cold oil into a cool or warm pan, and heat or continue heating over a low burner in a low oven. You may or may not wipe out any excess oil with a paper towel. If heating over a low burner, you want to remove the pan from the heat just before or just after the oil starts to smoke. If heating in a low oven (275F is great), turn the oven off after about an hour.
Drain the pans if necessary. Wipe with a paper towel if not too hot to handle.
If in the oven, some people like to turn their pans over and allow them to drain into a baking sheet while they cool. Either way, allow the pans to cool completely, wipe off any excess oil; then rub them with a little fresh oil, and store.
Do not use an oil with an aroma, e.g., a nut oil (including peanut oil) or an olive oil. The aroma will linger and contribute to whatever you cook for ever. Instead, use something light, with a high smoke point, like vegetable oil, corn oil, canola oil, etc.
When the pan gets dirty, you can wash with soapy water as long as you don't scour. If you scour, you'll have to re-season from scratch. You may use a sponge or any sort of non-abrasive brush, but do not scour.
Some people like to clean carbon steel or cast iron pans as they would a wok. That is, by boiling a little water in it, and swooshing it around with a non-abrasive brush.
Some people only wipe and do not wash, ever. I think there are problems with the approach, but to each his own.
Every time you wash the pan, oil it in and out to prevent rust and to keep advancing the seasoning.
Once the pan is fully seasoned it's seasoned. The seasoning in your grandmother's pan, jealously guarded for sixty years, is no better than a new, fully matured seasoning. A completely season takes a couple of months of frequent use.
As said at the outset, there are lots of good ways to do this and I'm sure you'll get lots of advice.
Hope this helps,
PS. We have two skillets from the series, and like them a lot.