shoe removal

I just ordered some shoes and bars to fix an aluminum window. I simply could not figure out how to remove the old ones without bending the channel with a pry bar, so I'm being optimistic of bending it back and it working. There are no cut outs that I can find, nor the manufacturer of the window. There doesn't seem to be enough flex for your spreading tools, either. I have a second window to do, and it would seem that there has to be a way of removing these things. Any suggestions or ideas?