Here is a YouTube video showing the procedure.
I was worried about that very issue about half way through building this sheath. It sounds good in my head and not so much when finished crossed my mind a few times...Beautiful work! I really enjoyed following the build.
The blue in the sheath really does compliment the handle well, good choice. I know sometimes it looks great in your head but doesn't come out quite the same in reality- I think you nailed it.