Eclipse should be able to help you out with most of it.
Just type that in, wait a sec for Eclipse to register it, hover over it and see if your proxy appears in the suggested imports list.
Also, yes that is correct ;)
You can either use
documents.proxies.DocumentRepository throughout your code, or add
import documents.proxies.DocumentRepository; to the header of the file, and use
DocumentRepository in the file. As Robert indicated, Eclipse will suggest you to do so if you click the error message. (If a name collision occurs you have to stick to the first solution, but that is not very likely with this proxy name).