I asked my professor to write me a recommendation letter for graduate school, but now my plan of attending graduate school has changed. instead of going to graduate school, I will try to find a job, and get more work experiences. I know that my professor has not written my letter yet, because he said he will write it after he received request emails from graduate schools. so how should I recall the request?
Why not just write what you just did?
Dear Professor X, A while ago we talked about whether you would be willing to write a letter of recommendation for me. I have given this some more thought and have decided, instead of going to graduate school, to try to find a job in industry instead in order to get more work experience. For the time being, at least, I will therefore not need your letter after all, though I appreciate your willingness to provide one. I might come back to your offer at a later time if I decide to go back to graduate school! Sincerely, Y