Doop skates have a very useful mechanism called Quick Release System. It helps you to find out what size do you need. You can watch here a video to know how it works:

http://doopshop.com/how-to-adjust-your-doop-skates-to-your-size-using-the-quick-release-system

But some skaters want to remove the QRS. If you are a strong skater and/or you don't like the extra shock absorver, you can remove the QRS and change it by mounting a simple anti-rivet and screw.

Watch the next video to know how to do it: