Welcome to cosplay.com!
There's a lovely, although long, Bleach thread here
You can search that thread for your answers - I know for a fact that there are instructions, as I found a few of the websites. And someone else mentions a site where you can buy similar ones.
To search that thread, click that link, then look above the page numbers on the first page in the purple bar. It says "search this thread". All you have to do is enter the word you're looking for, and it will bring up all the posts with that word. Words have to be more than 3 letters long.
The sandals are called "waraji"; basically a woven straw sandal.
Good luck with your search!