set up links to correct fb, twitter etc, deleting 2nd set of buttons

Hello, I am trying to assign my FB page, twitter account etc. There appears no option to actually set up the correct links from the buttons to the accounts. In "my account" there is no option for this. So, where do I do this? Also, I would like the buttons to appear only at the bottom, not at the sides. There appears no option to actual stop the side buttons appearing, only the position changes.