Hi,
You can't remove it yourself. You could send the buyer a feedback revision form and ask if he would consider revising the feedback, but having read the feedback I think he would be unlikely to do so.
You can only send so many revisions a year, so it's something you'd need to think over.
Did he contact you before leaving the feedback, and if so, did you try to resolve the problem?
It may not be too late to resolve the problem, if you ask if he would like to return the item for a full refund.
This would not guarantee he'd revise the feedback though, sorry.