This evening I have upgraded my friends Wii firmware from version 3.0e to 4.2e. Before I upgraded the Wii firmware I first installed the Homebrew channel (1.0.6) and hidden DVDx channel with the Bannerbomb exploit. This hack is really easy. It took my only 5 minutes to complete all steps. After that I successful upgraded the Wii firmware to 4.2e and installed all (new) available Nintendo channels through the Wii shopping channel. This took about 45 minutes.
Conclusion: Installing the Homebrew and DVDx channel was never so easy. I hope lots of other Wii owners will upgrade there Wii and will explore the world of free Homebrew software. 😀