Maybe its different with the Dorman but I did my plugs in about an hour start to finish with the stock PI intake. Magnetic spark plug socket and a long extension and they all come right out easy.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.