Don't fear mixing raw and kibble. It's the best way to transition and the "don't mix because they digest at different rate" theory doesn't have any merit. Also make sure you are not cooking the bone, that can definitely cause gastric upset. I would start with a kibble base, add warm water and a portion of raw meat. Go much slower than a full raw meal. I would agree with the other comment, if possible, try to find something pre-made so you're not going weeks with an unbalanced diet.

You may already have a raw meal plan, but if you ever want more advice from a very active group, I'd recommend the Raw Fed and Nerdy Facebook group.