I took all the dealer decals, and pinstriping off of my '95 Camry this past summer. It was almost 100 degrees out the day I did it and they came off quite easily. As Twista616 said, just take your time.
If you use a heat gun be VERY careful. I've read posts recently where people burned their paint and one guy even melted his tail light with a heat gun while trying to get decals or pinstriping off. A hair dryer will provide sufficient heat and be much safer, or just do what I did and wait for a hot summer day.
After you get them off, you'll need to clean the leftover adhesive off. I used "Goof Off", on most of it but you have to be real careful with that too. If you leave it on too long you can mess up your paint. I just did a quick wipe with it and didn't have any problems. Other people on the forum have recommended other products to get the adhesive off. Do a search and you'll come up with some products.
On my Camry, there were "ghost" images of the decals and pinstriping left behind. After a good polish and wax, you can only see them if you're looking for them, but they're still there if you look hard enough. Still looks 100% better without the decals/pinstripes though.
Good luck!