If you have never undertaken anything like this before, my advice would be to take it to a competent garage or mechanic, and have it done there. The last thing you want to do is install your new gears and f**k up the backlash and then destroy them. On top of that the front end is going to be a lot tougher to do because it will need to be dropped down to put the new gears in. Just my .02 cents. Good luck.