Assuming that you’ve got the Homebrew Channel loaded, head back to your computer. Download both of these zip files from here: Link (mplayer and DVDX)
Once downloaded, click the README file in each and give it a read. If you don’t want to, then just extract them directly onto your SD card within the “apps” folder. If you don’t have an apps folder in your SD card’s main directory, then make one.
What your SD Card should look like
Start up the Homebrew Channel
Now that you have the other folders placed into your SD, take it out of your reader and put it back into your Wii. Then boot up the console and load the Homebrew Channel.
This should be in your apps list
Once you’ve selected on the bottom app, you should get this screen. Pick the basic install and let it run its course, which should be all of 15 seconds.
You’ve installed it!
Now we’re getting close to the end of our journey. Once you click on the Mplayer app and it loads, you’ll be pushed to the main menu of Mplayer.
MPlayer is up and running
This is the main menu for Mplayer. Nothing fancy, but when you put a DVD into your Wii, magic will happen. Once you have a DVD inserted into your console, use the Wiimote d-pad and scroll down to DVD-Video. Select that and your movie will start playing!