I just added a pull start, can I still use the easy starter to ignite the glow plug? Can I now remove the black and red wires? Thanks

You probably could but your better off buyin' a new glow heater.
BNZ'

Yup, Bonefrost is right, get yourself a glow plug igniter, it would be a major pain to try and pull start your motor while pressing the button on your easy start. You could probably get an inexpensive one for around $15 or so.