I only have the pics for info

Thanks for reaching out to us, Trish. You will have to remove the doors from the track to replace the rollers. There should be a bottom door guide like the 23-234 to prevent the door from jumping the bottom track. With some help, have someone with a putty knife slide across the track where the bottom guide is and push in the locking tab as the other person pulls up on the door and swings the door so you can unhook the wheel from the top track. With the door out you can replace the rollers and reinstall the door by first hooking the wheels at the top track, swing the door above the bottom track and locking the bottom guide back in the track.

Take a look at the 23-016 roller. This looks similar to your old one but review the specifications and see how they compare with yours. 

Dimensions for 23-016