You'll need to:
1. Safely raise and secure the vehicle: Use jack stands, never rely solely on a jack.
2. Locate the starter: It's usually on the passenger side of the engine block, towards the bottom.
3. Expect two bolts: Most starters have two bolts securing them to the engine block. They're usually 14mm or 15mm, but you'll want to double-check with a socket set.
Because accessing the starter requires working underneath the vehicle and potentially dealing with hot engine components, this is a job best left to someone with mechanical experience if you're not comfortable working under your car. Improperly working under a vehicle can be extremely dangerous.
Before you begin, consult a repair manual specific to your 2003 Dodge Caravan's engine (3.3L or 3.8L). A repair manual will provide detailed diagrams and instructions, including the exact bolt sizes and locations for your specific model. You can find these manuals online or at auto parts stores.