the black plastic cap (where you step) on my side steps is cracked and worn out.is this part even out there? I have been searching but can't find it.

 

I found this, assuming you mean the rocker panel ??
If you mean the "door sill plate", then you may be right, they are hard to find, if at all.

2006 2010 Hummer H3 RH Passenger Side Rocker Panel Molding New Gray 15817835 | eBay

 

Thanks, sorry for not being clear. I have the chrome tube side steps/bar. The black pad that you step on is what has cracked and worn.

 

Lots of people have dumped their nerf bars. You might post up asking if anyone has what you need on a takeoff set.

 

Here is a picture
<a data-flickr-embed="true" href="https://www.flickr.com/photos/cardiac/21221012918/in/album-72157658191553659/" title="side step"><img src="https://farm1.staticflickr.com/715/21221012918_7f4de8b5cc_k.jpg" width="1152" height="2048" alt="side step"></a>

 

I have two sets of the black side steps, I'm sure your could buy one of those sets and get all the spare parts you need.

 

thanks. i found them for $40...I will give you $45 for both sets of side steps shipped to my house (just kidding of course).

 

Glad you found them and at a reasonable price.