looking for mechanical advice on a '97 GT...

[lil drummer boy]

I'm not all that mechanically inclined and recently my stang has been riding like it's missing a cylinder. It hiccups when accelerating from a stop or when going up a hill when the engine is put under increased stress. It's well past due for a tune up and I assume it's either the plugs/plug wires, fuel filter or clogged injectors. I figured I'd start with replacing the plugs and plug wires, however when I started I found the spark plug wires were snug as can be and no matter how hard I pulled I couldn't get them to pop off of the plugs. Am I missing something? Is there a special tool I need to remove them or are they just stuck? Any advice would be greatly appreciated. Thanks!