Unless your Wii is connected to the official Shop Channel (now mostly defunct) or updated via a game disc, you have to hunt for the WAD file manually.
: Do not download files labeled with this string. If your device prompts you for a legitimate update, always verify it through your official Settings menu (e.g., Settings > General > Software Update on Apple devices). NX405 Software Update Instructions (for APP, MPEG and MCU) ios5664v5661wad updated
If you can tell me what you are encountering or which homebrew tools you are using, I can help you troubleshoot the installation more effectively. Unless your Wii is connected to the official