This is my first entry in the Fantasy Premier League

I have no idea how I managed to get my goalkeeper (Alisson Becker) to be vice-captain and a striker (Joao Pedro) to be be captain. I did not realise until now that I could select them and earn extra points from them.
Well, I tried but cannot work out how to change the captain and vice-captains. Maybe I am missing the obvious but nevertheless, can they be changed?
Welcome to the fantasy pool, what's your team name? Can't find you in the league.
Well, you can not longer change your captaincy option until the GW is finished. ( FPL rules are different from FIFA and UEFA fantasy rules ) Wait and make your changes before GW2 deadline.
Thank you Konsa for the RED- easy sub