To begin making big changes in your life it can help to change little things first to build your confidence, helping to reduce the fear of the unknown.
So why not try changing the hand your brush your teeth with. I have been doing this for a while now and each time I do it reminds me how challenging change can be.
For example, the muscles in my left hand are just not used to working in that way. It is so much quicker and easier to use my right hand. But after several weeks of determination and desire to change, I am finding it much easier.
This can be likened very much to the mind. For to change old patterns of thoughts can take longer than you hope, but if you are determined and desire the change, you will make it happen. So try the toothbrush first. Allow your body to get used the idea that you can change. Show yourself how much you can achieve even when at first it seems like an almost impossible task.
Most of all, laugh lots and have fun doing it.