I'd use a file for that, simply because clamping the mudguard would be a massive pain in the arse.
I'd use a rotary burr in the DremelĀ® for exactly the reason I wouldn't use a hand file - lower tool pressure from the DremelĀ® gets around the work holding problem.
@Dammit started
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I'd use a file for that, simply because clamping the mudguard would be a massive pain in the arse.