Install a file archiver that supports 7Z files, such as 7-Zip, WinRAR, PeaZip, or The Unarchiver
Download and install the app on your device
Right-click the 7Z file
Select the archive app from the Open with menu
Open the file in the archive app
Choose Extract or Extract Here
Select a destination folder if prompted
Enter a password if the archive is encrypted
Open the extracted files from the destination folder
On mobile, use a compatible archive app from the app store
On macOS, use The Unarchiver or Keka
On Linux, use your file manager or install p7zip
On Windows, use 7-Zip or WinRAR