You don't.
[my personal take: just tell her you love her and show/prove it to her -- para walang assumptions and confusions]You show her.
You be her friend.
You be there for her when she needs someone to talk to.
You cry with her when she is sad, and you are happy for her when she succeeds at something, even if - no, make that ESPECIALLY if - she does that thing better than you do. And you do all you can to see that she succeeds at things often.
You give her what she needs, when she needs it, emotionally I mean, not "things."
And if you do really love her, not just think she is hot, or are infatuated with her, you will do all this expecting nothing in return. And I mean NOTHING.
If you expect anything from her, you do not love her, you just want to be loved by her. Everyone wants to be loved, but to be loved, you must love.
If you do these things well, one day she will come to you and confide in you about something she feels badly about, because, if you do these things well enough for long enough, it will be you she will want to confide in. When she does, you make sure she knows that it matters to you that this bothers her. If you have advice for her, save it until you are sure she knows you care, and that her feelings matter very much to you.
Once you are sure of this, you may offer your advice, but know that the caring is more important than your idea of how the problem might be "fixed."
Loving her is not admiring the way she looks or anything else about her. These may be among the reasons you are attracted to her, but they are not acts of loving. Loving her is a series of actions, things you do for her, for no other reason than you love her.
Loving her is not wanting her to give you attention, or to give you anything for that matter. Loving her is wanting to give, not get. That is how you love someone. You give to them all you can give and expect nothing back. Once you have done these things well enough for long enough, and her eyes tell you she longs to hear you tell her, then you will have earned the right to tell her how much you love her.
