Welcome to the org!.... first off, this is the interior section.
Secondly, only buy OEM glow plugs from ford or international. I belive they are made by BEAU?? Its a german company. To get the pass side valve cover off you will need to remove the vacuum resivor on the ac box undernieth the foil wrap to give you clearance. Or remove the trans dipstick like i did, but you dont wana do that.
Inspect you under valve cover harness while you have the valve cover open as they may have bad wires. Again, only quality parts here as the junk ones will cause you problems. And may as well replace the glow plug relay while you are there. U can get a package combo from paul at Complete Performance with a stancor relay and oem plugs. Its the way to go!
Otherwise the job is pretty straight forward. Remove what u think need to be removed and you will be good. And if the glow plug doesnt come right out, be careful as the tip may be swelled and you dont wana pull hard and break the tip off in the combustion chamber