They are a 13mm bolt.
Mine wouldn't budge and I said eff it and went to put in back and when I folded down the arm and unfolded it again, it came off
Powercoating is much better. Spend the money for that, and you'll never have to do it again. Either way, take off all the stuff on the wiper arm (spray nozzles, hoses, etc) If you get them powercoated, you'll have to take them off anyway

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2000 Olds Alero 3400 SFI 14.53 @ 94.93
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