I associate love with freedom. If you try to change someone then you don't really love them, instead you love the person you want them to be, a person that does not actually exist.
If there is something you do not like about someone or something you'd like to see them improve upon by all means share your thoughts if you so choose, but I urge that we leave it up to the individual to decide for themselves what they whish to change and what they wish to improve upon. Let us not force others to conform to our ideal through manipulation or physical force, but instead merely present them with our opinion and allow them the freedom to choose without repercussion from you or I.