How do I clean charging port

If you have a can of "Compressed Air" for cleaning computer keyboards and such, a short blast or two is helpful after first using a flashlight and a wooden or plastic toothpick to get out any items you can easily see. If that does not work set up a visit to your local Apple Store. Don't force anything. Contact Apple Support

Very carefully, with a non-conductive tool. I'd suggest a plastic or wooden toothpick.

mdhurst wrote:

If you have a can of "Compressed Air" for cleaning computer keyboards and such, a short blast or two is helpful

Apple specifically recommends against using compressed air.

How to clean your Apple products - Apple Support

Do it in very good light. If you have one, a magnifier helps. Use something non-conductive like a wooden toothpick or a dental floss pick. Gently pick out any pocket fluff or other debris that has gotten lodged in the port. Take your time. Stuff can get jammed all the way at the back.