I've done it. It's VERY simple and is incredibly unlikely you will actually do anything that will cause your Wii to malfunction. The trickiest part is making sure you have everything in the right folders and all the folders in the right directories, so it really isn't difficult at all.
However, I did not mod mine to be able to play burned copies of games (except to get around region locking, but I actually legitimately own those games too). If that's what you're after, I'm not sure how the process goes.