Here are the two most common scenarios for adding the wrong ink. Follow this step-by-step guide, and you can handle it yourself.
First scenario: The wrong ink has only been added to the ink bottle, and hasn't started flowing into the system at all. This is the simplest case.
Simply pour out all the wrong ink from the ink bottle, rinse the bottle two or three times with clean water, thoroughly cleaning away the wrong ink from the bottle. Then place it in a well-ventilated area and let it dry completely – not a single drop of moisture can remain. Finally, add the correct ink, and the printer can be used normally again. This solves the problem at zero cost.
Second scenario: The ink has already started flowing, and the wrong ink has entered the ink lines.
In this case, don't rush to throw away any parts. First, empty the wrong ink from the ink bottle, then use industrial alcohol to repeatedly clean the inner walls of the ink bottle, dissolving any residual wrong ink. After cleaning, place it in a well-ventilated area to dry completely. Then add the correct ink and gradually let it flow through the system, flushing out any remaining ink in the lines. Once that's done, the printer will return to normal operation.
In fact, adding the wrong ink isn't really that scary. The worst thing you can do is mishandle it and damage the printhead. As long as you distinguish between these two scenarios and follow the steps – cleaning, drying, and adding the correct ink – the problem can almost always be solved.