possible to undo blocking?

[Wnderlnd]

I really hope I haven't ruined my just finished hat! it is made of 100% merino wool and the brim fit but the top part needed a little blocking, so I spritzed it and put it over a small bowl. I thought I was very careful not to get the brim damp/wet, but it still stretched as well.

Is there a way to undo the blocking so the brim will fit again? It isn't horrendously big, but enough that it isn't quite right.