Having searched through Google there are numerous ways to remove an iron on badge but I've no idea how good they are.
1 - Soak the jacket in water with 'Goo Gone' (might be an American product) and brush off with a toothbrush after 2 minutes. You might need to look for a glue remover.
2 - Use from Brake Parts Cleaner. Apparently it removes it completely, don't know about what it does to the jacket though.
3 - Use parchment paper (?). Iron that over the transfer for about 45 seconds and remove. They say parchment paper is available from grocery stores (??)
4 - Alternatively this is a post from a female called Abby - "Here's how I did it first I wet the area and subsequent area around the transfer on the material in my case a t-shirt and then ironed directly onto the transfer with a hot iron/cotton setting (no protective sheet) and made cirular motions over the transfer until it melted and began melting together into little balls. From there I picked off the balls and used a lint brush the ones you can get that are made with sandpaper or the metal comb looking ones to scrape off the stubborn bits like taking off lint from your clothes. I repeated this action untill the transfer was off. The only down side is that you may not get it all off in some cases but hay it's worth a try considering they say you can't get it off any other way" No idea how sticky your iron will get though.