If you need to change the PayPal address you used for a purchase, you can do so by contacting the seller and requesting the change. The seller can then refund the original payment and send a new invoice to the new address.
If you need to change the email address associated with your PayPal account, you can do so by logging into your account and going to the Settings page. On the Settings page, you will see the option to change your email address under the Email section. Once you have changed your email address, you will need to confirm the new address by clicking on the link that PayPal will send to your new email address.
If you need to change the PayPal address you used for a purchase, you can usually do so by contacting the company you made the purchase from. Many companies will be able to update your payment information on their end and send you a new confirmation. If the company is unable to make the change for you, you may need to cancel your purchase and start over with the correct PayPal information.