I worked through this with my 8 year old. There are practical pages, where you can draw pictures and there are tasks to provoke a discussion. It also gives practical advice about relaxing- the breathing technique really helped us.
It has made a big difference to my child and I would recommend this to any parent dealing with an anxious child. You do however, need time and space to work through this together- it isn't a quick fix solution, more a long term strategy.