I have never prepared roo sinew but it is probably similar to deer. Once you remove the tendon from the roo remove the casing around the tendon bundle and separate the tendons to the appropriate size. You can do this either wet or dry I believe. If you have dried sinew already, pound the sinew with a flat hammer or mallet on a hard surface to break up the tendon bundle then separate. I chew dried deer sinew to moisten and soften it and to prepare it for application. The sinew mixed with your saliva makes it's own glue. When pliable make the wrap tight around the area and when you come to the end of the sinew lick your fingers and go around the wrap a few rotations. This will tighten up the wrap. Once it dries, the sinew will shrink and tighten even more. When dry, seal with water proof glue or other sealer. I like pitch varnish made by dissolving pine pitch in alcohol, straining it and store it in an air tight container.