This is primarily the most frequently asked question. There are multiple posts (with code examples) on various methods to do this. There is also a demo (called YAF Blend) in here too.
Try searching again, usinf "intergrate, blend, single signon" as keywords. You will find your answer. Keep in mind, each integration is different. Any answer you get will still require diving into YAF code.
.....the man in black fled across the desert..........and the gunslinger followed.....