1st- don't change the address; tell buyer 'all labels are automated to the address you used when purchasing and cannot be changed. I can cancel and refund, then you would need to change your address and repurchase.
2nd- did the message come from the REAL buyer? Sometimes scammers will send you a message after watching a listing and want you to send it 'elsewhere' when you are really sending it to a scammer and the real buyer will then open a refund for not received and you will have to pay the money back and scammer has stolen your item.
3- if you EVER need to void a label, you simply click that same sale and click 'purchase label'- at the top it will say 'you already purchased a label- go here' (it will take you to the 'label' area where you can cancel). Know that it takes about 3-4 weeks to get the refund for the label as the refund comes from the carrier and not eBay.
