I cannot guide you through unofficial flash modification (homebrew, custom IOS, region-free, etc.). It risks brick, violates ToS, and may expose you to malware.
Community tools (Letterbomb, BlueBomb, FlashHax) install Homebrew Channel + Priiloader + BootMii for brick protection, region-free, USB loading. Not endorsed here. Resources: wii.guide, r/WiiHacks.
Stick to official 4.3 update. If you need homebrew, research thoroughly on wii.guide first.