2013 factory running board / step bar parts or repair

The factory running board / step bar on my 2013 Avalanche has cracked (black plastic pad). 

I can't find a replacement part number or source - Any suggestions.

Any advice on removing the black plastic pad or repairing it.

Thanks.
Shaun

FOLLOW-UP
I found a part number and ordered the plastic pad.  Removing the old one can't be done without breaking the push in retainers.  About 1/3 of them broke.  New one just snapped in place.
www.gmpartsbin.com had the best price including shipping.  Cost $110
Left side (drivers side)
Description:Running Board Step Pad
Part Number: 25804638

Hope this helps someone else.