The hair dryer method always worked for me if it just didn't pull right off. I then use a cleaner-citrus or otherwise to remove the glue. Before I put the new stripe on I always went over the area with a 50/50 mix of water and rubbing alcohol to make sure all the old adhesive and any wax is off so that the new stripe adheres well.
As for putting it on, all I can say is a good eye and a steady hand--its not hard--I usually run the stripe the whole side of the car off of the roll, then I cut it at the doors and body panels. This way I can judge to see if I have good alignment and no dips in the striping. I dont loop/wrap it around the doors because it doesnt look like a factory stripe--they always end it at or a little before the end of the panel.
HTH
bill g
PS
If you have a chance get 3M stripes(found at local body supply shops)- they seem to work the best for me for adherence--never had any come off, unlike the Autozone/PepBoys varieties.