How do you change the spark plugs on a 91 Buick regal?
open engine hood locate distributor(has a bunch 6-8 of plug
wires coming off of it) follow plug wires to the engine remove by
twisting and pulling gently on he boot(thick part) of the wire only
remove 1 plug wire remove the exposed spark plug (with a plug
wrench /socket) under the wire you just removed replace with a new
plug properly gapped & of correct heat range and size for your
specification of vehicle repeat until all are done.