Even though I liked how my hat turned out I didn’t like the placement of the design. I decided to try and get it out. After an internet search I found this video
While I used glitter and glue instead for the design and a scrub brush instead of finger nails or a butter knife it still came out. I’m sure it helped that washed it before the glue was set.
I will be re-making the hat, when I get the sample of iron on vinyl that I ordered. (lucky for me a sample was big enough to fit the design I chose and only cost 99 cents)