By setting in the pen each day they get to know you and trust you. All of the guineas I have will let me hold them and some of them was wild when I got them. In the winter they stay in the pen they can leave if they want I put a heat lamp above there perch. I worm them twice a month. As for feed they eat a lot of bugs and weed seed I do have turkey feed if they want it.
Guineas are roamers but once they make a home they stay.
I don't know how long they live my birds are at least five years old. Look at them as a care free chicken.