Thanks for your question!
First, the ability to scrub around in a video when you have recorded as a Live-to-VOD asset should be automatic. Once you have been provided with the m3u8 URL, you can insert this into a player and can move around in the video as needed. It is important that the player supports this, and most, but not all, players do. Wowza Player does as does Theo Player which can be tested at:
The ability to rewind a live video is controlled under the Stream Target settings for your stream. These can be accessed though:Advanced->Stream Targets. Choose the stream of interest, and on its properties tab, choose edit, enable “Playlist seconds” and set the value to your desired rewind duration. Right now, this is limited to 200 seconds, but we are in testing an increase it to a few hours, so assuming no problems are found, you should see this option expand in the next week or two. Stay tuned! As above, the player needs to be able to support this as well.
I hope this helps!