Is it possible to manually clean the print head of a Canon G2000, and what solutions are safe to use?

Yes, you can manually clean the print head. Use distilled water or a dedicated print head cleaning solution (available online). Gently dab a lint-free cloth soaked in the solution onto the print head's electrical contacts and nozzle plate. Avoid harsh chemicals like alcohol, as they can damage the print head. Never touch the heating element.