Can I replace just the adapter piece that plugs into the wall?

I suggest you pay US$20 for an 'extension cord' that fits in the place of the small wall adapter (not sold separately by Apple)

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Hi Angie926,

We'll be glad to assist. We're not entirely sure which part you're referring to, as there is no magnetic section that plugs directly into the wall as you've described.

You can find any and all replacement parts listed on Apple's website here: Apple

We hope this helps you out.

Cheers.