BobCat 863 changing the glo plugs

Is it necessary to remove the injector fuel lines to replace the plugs? If not is there a recommended tool to remove them? There doesn't seem to be enough clearance to get a deep socket in and not enough throw room for a ratchet.

How would you bleed the air out of the injector fuel tubes after replacing the glo plugs?
Thanks, JB

BobCat 863 changing the glo plugs