Actually it's quite safe and simple. I was in your position too ... but I'm very happy now and my money are spent well (on 650D). Just follow the steps in nanomad's post http://www.magiclantern.fm/forum/index.php?topic=7473.0 ... but be carefully with MacBoot (http://www.zenoshrdlu.com/macboot/macboot.html) ... there's a OSX Mountain Lion version you maybe take in consideration if your OS is OS X Mountain Lion or OS X Mavericks. Everything else is very well explained.
Good luck!
Good luck!