There’s no need to hire an expert to change the oil on your WaveRunner. With an oil extractor, user manual, cloth rag, and replacement oil, you can do the job yourself. Start by using the manual to locate the WaveRunner’s filter and then use the oil extractor to pump out the oil, which should come to about 2.4 quarts.
Next, set out a cloth rag under the oil filter and remove the old filter. Lube the new filter and then place it back in the WaveRunner. Then add the new WaveRunner oil, paying careful attention not to add too much as that can blow out the engine. Finally, test the WaveRunner for about a minute and then check the dip-stick.