Ok, now we're going to make your Wii even better and more 1337 haxx filled! The first thing we're going to get is the Trucha Bug Restorer. This will open your Wii to be able to install more programs that enable very useful hacks. Make sure to create a BootMii backup before doing this!
First, download the file by clicking the link above to download the TBR file. Once downloaded, create a folder on your SD card called "apps". This is where every single one of your homebrew apps is going to go. Once that's done, put the TBR folder inside of the apps folder.
Insert the SD card into your Wii and launch the Hombrew Channel (A.K.A. HBC). You should only see one app in here: the Trucha Bug Restorer. Click on it (Wii remote and GC controllers both work), and launch it. When launched, you can select the IOS to use or press B to continue without the IOS reload. I suggest pressing B.
First, select Downgrade IOS15. Then use the d-pad to select Downgrade from NUS. Press A to continue.
When another option comes up for file selection, it should say "Load from SD" first. Use the d-pad to change it to "Download IOS from NUS"
Here's a tutorial video for the Trucha Bug Restorer for an example to walk you through it. If the online method doesn't work, just download the WADs from the video description.
Once the Trucha Bug is restored, you can now install Priiloader. This program allows you to automatically boot to any application, which you can install to the Wii through Priiloader, install system hacks like a disc update blocker, movement of the disc channel, copying of large save files (Brawl save file! :D), and many more. Click the link to download!