Best practice for modifying public_nav_main?

[Tyler Mobley]

I'm working on a new theme for our digital library and am trying to add some framework specific markup to the primary navigation for a JS-driven dropdown. All I really need to do is add an ID to the child ul and a 'data-activates' attribute (value the same id as the child ul) to the parent ul > li > a link. What would be the best way to approach this? I know I can just grab the whole navigation ul as a string and start chopping, but that doesn't sound too efficient!

Thanks,

Tyler