Apple pruning - duo trees

[olrose]

I am thinking about planting an apple tree with my kids. I have spotted a duo apple tree that has a cooking apple and an eating apple on it - www.pricedropdonkey.com/cheap-food-drink/fresh-food-deals

How do I prune this tree. I have read about pruning apple trees and it has gone over my head, even though I have read the article a few times. Does anyone know how to do this and can explain it, in short and in terms that I can understand?

[shovetheholly]

These are tiny patio trees, so they should be easy to keep in control. I doubt you'll need to do anything more than maintenance pruning: keeping it in a nice open bowl shape and removing any branches or twigs that are crossing to avoid disease.

[pennyp10]

The main thing is to remove any branches that direct themselves back to the middle of the tree. Shape wise, think of a diamond, narrow at the bottom, fat in the middle and narrow at the top.