Remove air from ink system syringe tool
You will only go in about a 1/2 inch. You have to be careful not to poke a hole in the ink tube system. You will remove ink and air until the only thing that comes out is ink. You will then re-install the printhead.
You will need to run the printhead cleaning procedure a number of times to get the printhead refilled with
ink by the ink supply system in the printer.