a good adjustable heat gun is best. take it slow. use needle nose type pliers to get started and peel back slowly as the glue softens. don't force it. i first focus the heat on patch/d-ring ect to heat it up thoroughly and then as i peel it up focus on the glue between the patch and tube. again, be patient and don't try to just rip it off. let that glue soften.
it's really pretty easy. just be careful and don't set your heat gun on your raft tubes when done...or rags soaked with toluene.
no idea on the hair dryer.