Easy as hell, unless some idiot put a Dorman intake on it at some point...
Only use OEM COPs or rebuild the OEM ones on there with new boots/springs if they are in good shape. Make damn sure to use anti seize and a torque wrench. 12 ft lbs and no more. I did a big how-to thread in the DIY section. Mine is a 98 with plug wires but its near identical as far as actually doing the plugs.
2000 Mustang GT Steeda build #48. Bolt ons, suspension, Novi 2000.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.