Yes you should be able to take them out.
We have the store bought ones, they work like this... the end of it is kind of like a button, it slips into the hole of the shoe, you can put it in and take it out, the shoe hole acts like the button hole. The shoes are kinda stretchy.
I think the plain doodads come in two pieces and once you snap that together they don't come apart.
clear as mud?
eta: posted same time as lroberts324, didn't mean to repeat!