If your receiver is still functional, always back up your current channel list and settings before applying a new flash dump.

Format a USB drive to FAT32. For best results, use a drive with less than 32GB of capacity.

System recovery, software repair, and factory restoration How to Use the Flash Dump File Restoring your Star Max A20

Use a utility like WinRAR or 7-Zip to extract the .bin file from the downloaded .rar archive.