I didn't put exact amounts because it all depends on many lemons you have. Cut lemons in half, liberally coat in kosher salt. Stuff lemons in a jar and pour in additional salt to cover. Now add enough fresh lemon juice to cover. Refrigerate for at least 3 weeks before using. They will keep for a heck of long time in the fridge... I still use mine from last year!
It sounds like a ton of salt, but don't worry. You're preserving the lemons. All the salt gets rinsed off before you cook with them.
Mellow lemony goodness.