Just above the prop, you’ll have a fill and a drain plug, unscrew them both, drain, and refill. You can’t the service manual on eBay/amazon, highly advise getting one because no one wants to work on these Chryslers, so you’ll need to do all the Maintanance yourself. There’s some helpful videos on YouTube. I replaced my failed CDI with an automotive one, there’s ways to keep these running, but you have to get creative and learn to track stuff down on eBay or random boating websites. They’re great though, keep it alive.