Holland, praying for those we “dislike” or even “detest” is a central challenge for many of us. One needs to come to grips with the difference between “love” as a feeling and “love” as an active verb. God principally works through people, not through direct intervention. We are channels or mirrors of God’s grace and love. If you try, he WILL help you. Note, that’s not a “might” it’s a “will.” God does not make mistakes, and God loves all of us.
So, my advice is just to pray for this person, daily. A good prayer is to ask God to provide him with the same grace that you are asking for yourself. Phrase the request in your own way. Some say, “fake it until you make it!” Pray daily for this person (don’t try to take on too many people at once). In your prayer, ask God for the grace to make a sincere prayer for this person. This has always worked for me. Often it takes several weeks before I honestly find myself wishing the other well, but it happens.