Once installed, holding the Left/Rewind button while powering on will usually boot you back into the original SanDisk firmware if needed.
Extract the .bin file and drag it to the of your player. Sansa Fuze Software
Connect in MSC mode and move files directly into the Music , Photos , or Video folders. Sansa Fuze Software
Many users replace the official software with Rockbox to add support for more formats (like FLAC), customized themes, and games. Use the Rockbox Utility for automatic setup. Sansa Fuze Software