How do I change the state I'm registered to vote in?

I'm originally from MD, but I recently moved to Pennsylvania. This is a pretty stupid question, but how do I ';unregister'; to vote in MD and re-register in PA? Is there a way I can do it online?How do I change the state I'm registered to vote in?
You need to contact voter registration where you are currently living and fill out a voter registration card. They'll send you a new one allowing you to vote in Pa, you don't need to do anything about the Maryland registration.How do I change the state I'm registered to vote in?
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