How to pass a cdl license formal hearing after a DUI?

Honestly, it's pointless to worry yourself about it too much. For the next five years after you conviction, you're not likely to have any luck finding employment as a driver of any sort, least of all, as a CDL driver. If you find another job in another line of work (which you're probably better off doing at this point), you can apply for a provisional drivers license which will allow you to drive to and from work. Other than that, just make sure you have MVRs from any state you've held a license in within the past ten years, show that you've completed any counseling for your DUI conviction (whether voluntary or mandated), and hope for the best. You might get your CDL back, but don't expect to be hitting the big road again for a good while.