remove the interior panel and you will have easy access to the spark plugs and wire. good luck. and please accept my answer. thanks T-MAN
Fig. Access to the spark plugs is through the wheel-well on Astro and Safari vans
Fig. Disconnect the spark plug wire by pulling on the BOOT, NOT THE WIRE
Fig. A spark plug wire removal tool is recommended to prevent wire damage (and to make it easier)
Fig. Loosen the spark plug using a ratchet and extension . . .
Fig. . . . then carefully unthread and remove the plug from the cylinder head