Look at sidebar.php in the bp-default theme. It's located in the BuddyPress themes folder.
The Frisco theme is a child theme of bp-default and is actually using most template files from bp-default (like sidebar.php), so you'll want to override a couple templates.
To do that, copy sidebar.php and sidebar-footer.php from bp-default and put the copied files in your Frisco theme folder. Then cut the login code (lines 8-59) from sidebar.php in the Frisco theme folder, and put it wherever you'd like in sidebar-footer.php or even footer.php. You'll likely need to add some custom CSS to style the form/section again.