hello, you need to send a feedback revision request to your buyer to revise your feedback.
Click on below link :
http://feedback.ebay.in/ws/eBayISAPI.dll?ReviseFeedbackInitiate
Sign in into your account( IF SYSTEM ASK YOU TO ).
Now you will see feedback that can be revised. Now click against that feedback and click on "Send". You buyer will get a button to revise the feedback.
Make sure, you communicate with buyer first , if buyer decline your request, you will not able to send a feedback revision request to them at all.
you can ask buyer to send you message on ebay stating " issue resolved, remove feedback" and ask ebay customer support to remove feedback for perticular buyer.
Some people can go their whole lives and never really live for a single minute.