Loving them means caring for them, and it starts with your decision to love them. You will not drift into love; you must decide to love. And then ask God to help you, because you will only be able to love as God assists you in the realities of that concrete relationship. Ask God to show you something in this person that is good and for which you can be thankful. Let the Lord show you a good thing about them, and then love them by being thankful for them.