Sorry for late response. If you haven't worked it out yet, it's rather different to windows. After downloading the dmg file, if it doesn't mount immediately, drag & drop it onto Disk Copy program (Found in Utilities folder .. use the Go menu in finder to go to utilities folder.) After it mounts, double-click the program inside the disk image. Follow instructions from there. Then after installation, drag & drop the disk image into the trash which is the trash icon at far right of your Dock. You can keep LW program in your dock by holding your cursor onto the LW icon whilst it's in the dock & choosing keep in dock. Else drag & drop it to a new location in the dock. You can also drag items to the dock from any folder to keep there.)