Once Webrecorder Player launches, you can choose a local web archive file (WARC, ARC, or HAR) after clicking Load Web Archive
Once the archive is fully loaded (it may take a bit if it is a large file), you will be taken to the collection page, listing key bookmarks in the archive. If the WARC was downloaded from Webrecorder, the bookmarks should appear the same as they did online.
From the collection page, you may select any of the bookmarks to start browsing the archive. The navigation bar at the top center can be used to switch to page through available bookmarks, same as when browsing on https://webrecorder.io/
The back/forward/refresh buttons at the top left provide same functionality as in a regular browser.
You can even disconnect from the internet and continue browsing to verify that your browsing is entirely offline!