My advice: DON'T!!!
It's hoodoo-voodoo that not ONE legitimate user-agent for people with ACTUAL accessibility needs makes even the slightest use of. It's pointless code-bloat that at BEST should be redundant to your semantics or the content itself, at worst is a snake oil peddled fairy tale NOBODY is implementing to do what it's advertised to do.
If anything the only LEGITIMATE purpose it serves is to satiate the wants and desires of the same metadata junkies who used to make up their own "microformats" bullshit to try and make data scraping easier... and let's be brutally frank and call out data scrapers by their REAL names, "CONTENT THIEVES!"
Much like HTML 5's mind-numbingly idiotic and pointlessly redundant ARTICLE, ASIDE, NAV, HEADER, FOOTER, SECTION, and MAIN, if you have content of value marked up with the EXISTING structural tags of H1..H6 and HR according to the professional writing norms that HTML was based on, they serve NO purpose other than to make lame excuses to just crap more code into the page instead of putting content of value in there as ACTUAL content.
Again as I often say about a lot of the pointless extra garbage that is peddled as accessibility by people that have clearly never used a screen reader or braille reader, it's little more than dumping a can of shellac on a pile.
Though I might just be saying that as I'm not DUMB ENOUGH to crap JavaScript into a page in a manner that doesn't gracefully degrade when scripting is blocked, unavailable, or irrelevant to the user's capabilities. If you actually CARED about users with accessibility needs you wouldn't be writing your pages in a manner that NEEDED "aria roles" in the first bloody place since you'd be progressively enhancing content-upwards so it gracefully degrades!
But I guess if you're crapping Scripting only functionality, scripting only elements into the markup, not bothering to understand why headings have numbers, that paragraphs are for grammatical paragraphs, or why short lists of choices go into lists, whilst crapping all over your HTML with endless pointless presentational classes OOCSS style resulting in two to ten times the HTML needed whilst flipping the bird at accessibility -- throwing more code at it as if that will magically help might make sense.
MUCH like a great deal of HTML 5, Aria roles simply prove the people currently working on the spec never embraced 4 Strict and are unqualified to be making its successor.