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.
If you are attempting to install this file manually: ios5664v5661wad updated
: Ensure your system clock is synced; even a minute's difference can cause a "v5661" verification failure. Unless your Wii is connected to the official
Verify the SHA-256 checksum to ensure no corruption during the "wad" (Wireless Archive Deployment) process. 2. Sideloading & Installation ios5664v5661wad updated
: There are no documented "reviews" of performance improvements, battery life, or new features for this specific string, as it does not correspond to a public software release.