epson wf-2860 print quality is terrible, lines are missing. how do i clean the print head?

Clogged nozzles. Run a print head cleaning cycle. You cannot clean it if a cartridge is expended or critically low—replace it first.

1. Load a few sheets of plain paper.
2. Press the Home button.
3. Select Maintenance.
4. Select Print Head Cleaning.
5. Select Start.

Caution: Do not turn off the printer or open the front cover during the cleaning cycle.

After cleaning, select Check and then Print to run a nozzle check pattern. If lines are still missing, you can clean up to 4 times. If no improvement after 4 cleans, wait at least 6 hours without printing and try again. If still bad, contact Epson.