Approach Graft - Japanese Maple help

[remist17]

I need to fill in two areas on a Japanese green maple. I have done some looking at sites and I was hoping someone could send me a good link to a site that explains every step. I have never done this before.

My main concern is how deep you cut the tree. I understand you scrape off the bark on the doner branch. Just not sure how deep to make the cut on the tree.

Thanks

 

[RegnarBonsai]

Good site lots of info also has articles on approach grafting roots for better nebari

http://www.bonsai4me.com/AdvTech/ATApproachGraftingforBonsai.htm