How do I replace the timing belt on a 2003 Dodge Neon SXT?
First off..."Take your vehicle to a certified automotive technician"...very intelligent response....Anyway, Start off by cutting off your old one, easiest thing to do no sense wasting time pulling off a whole belt so you can throw it away.
Then, behind your first pulley(power steering) is the tensioner. It has a little triangle like spot that you can put an open end wrench on. I used an 11/32, however it was a little big so it might actually be metric. However I didn't have metric so made do.
Put your belt around all of your other pulleys first. They have a lip, so makes harder to try and get on them. Push back on the tensioner (from the top, towards the back of the car) slip the belt over the tensioner pulley, and you are done.
Hope this was more help then telling you to take to mechanic.
For a 2003 Neon, a car nearly identical to the 2005 version, you should figure $700 cost to replace a timing belt at a dealership. However, sometimes you can get a better deal as a small local repair shop. Keep in mind that this is for a replacement only, if the timing belt broke, there is a chance that the engine could have taken damage.