You may be able to pull the trigger/trigger bar out without pulling the sear cage but I haven't tried it. I would pull the grips, magwell, magbrake, main spring, safeties, sear cage, and then trigger. Make sure you don't loose the sear cage springs that are on the back of the sear cage (only found on the TS variants). You might as well deep clean it while apart.
Cheers,
Toby