[Olfart]

Don't pull by the wires unless you want to damage them... of course if you are replacing them who cares? Pull by the boot that is over the plug. You might be able to twist it loose and peel it back away from the plug. There is also an inexpensive tool at auto parts stores for grabbing the boot. When you install the new wires make sure to coat the inside of the boot with plenty of silicone grease...they will come off easier next time.
Replacing the hoses would be a good idea. Also take a look at your belt while you are down there...there is a cheap gauge available to check the wear..or better yet just replace it. And check belt pullys and tensioner spring too.