If I may suggest, you look up on the Internet How to make stuffed animals. Any good hobby or fabric store should sell those eyes. Then ask if the place can suggest someone to repair an animal for you. Many places have lists of craft people that can help.
If not, then try your sister, mother, wife, or grandmother, they should be able to repair your Rocky for you if you are not crafty yourself.
If there were repair instructions, they would have come with Rocky, and as I remember, there were none included.
This may open up a situation comedy moment, why not just put an eye patch on Rocky. He could be a rescue animal as well.