Edit Studio Theme Drop Down Bar

Two questions here!

One - I have installed the "Membership Premium" plugin to add paid memebers functionality to my site. How do I modify the "create a new account" link in the studio drop down panel to go to my membership plugin registration page. I do not want new users to go to the default BP url /register.......

Two - How do I modify the Studio Theme nav bar to show different menus depending on whether someone is logged in or logged out?

Thanks for your help!!