You can do what I did with my job a year ago...

"Mr. Woodward, can you sign this for us please?" (It was an agreement to productivity document)

"I'm not sure the wording on this quite fits for me... mind if I edit it?" I said while sitting in a conference room with the head of the department, the president of the company and a few other "suits"...

I scratched out the typed letter and wrote... "I QUIT!" as big as the paper would allow and then handed it to the president.