Sliding door rollers

Thanks for posting. We'd be happy to help you. This old roller guide is indeed discontinued, but the 23-222C is meant to replace it. To remove and replace this guide, lay the door on a flat stable surface, then remove the old guide with a pair of needle-nose pliers. You have to steadily work the hooks of the old guide out of the door frame. There's no real trick to this, it just takes patience and some elbow grease. You then reverse the process to install the 23-222C. Let me know if you have further questions. 

I agree, our 23-222C looks like a great replacement option. I believe it's just a newer version of your older Stanley brand part.

As for removal, it's fairly straight forward, even if it isn't exactly intuitive. These are usually just hooked into the frame, without any external fastener keeping them in place. Therefore you have to unhook them; to do this, I like to use a pair of pliers to gently--but firmly--work the housing out of the frame. It takes a little time and you have to be patient, but it will release.