If you have a 1000 word story which you need to cut down to 500, and you actually achieve that that by cutting down on unnecessary words (as opposed to cutting down on unnecessary ideas), then you probably have bigger problems with your writing.
If you have a 600 word story which you need to cut down to 500 words, then McLean's advice is useful.
I'm not criticising you for posting that link, by the way. It is probably more helpful and appropriate to this thread than anything I posted. I just get frustrated how so much writing advice seems to be focused on sound bites and easy to memorise concepts ("show, don't tell", "kill the adjectives"), that - as I said above - are good ways to avoid really bad writing, but will not get you anywhere near good writing.