So I've been looking into migrating an old web forms app and part of that would be to migrate the old sql membership provider. I've looked at a couple solutions including the asp.net identity, but honestly the couple I've tried have seemed so difficult I'm half way leaning towards just building my own. All that I really need is a new "user" table to hold their basic user info and password hash and salt. I have all their profile info in my own custom table already.

My question is, has anyone done this migration and if so, what did you use? I've tried a couple mock migrations so far and they've went horribly. All the tutorials out there for the pre built stuff seem to be as if you're starting brand new.