Tool needed to replace egr valve tube on 03 buick rendezvous

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Egr valve tube broke off inside egr valve. Now I have to replace both egr valve and egr tube. Can I just use a crescent wrench to remove the tube from the bottom part of engine? Or do I need a special tool? It's pretty rusty, can I spray WD-40 on it to help unscrew it? Or should I use something else like carb cleaner?