Keep a cool head and a level tone. Avoid turning the conversation into a fight where she might get defensive and retaliate.  Avoid victimizing or feeling sorry for yourself. The goal is to gain her understanding, not her pity. Keep an open posture. Stand straight with your arms at your sides. Don't cross your arms over your chest as this is commonly interpreted as a defensive stance. Focus on "I" statements to describe the situation. Look at her directly and say things like:  "I think you need to know how hurtful it is when you do "X." I feel hurt because "Y," and I'd like you to stop doing it." The situation isn't just about what she has done. It is about how you have become involved. Be prepared to forgive her and reconcile. Our minds have a tendency to blow things out of proportion when we feel upset. Before starting sentences with "You always" or "You never," ask yourself whether or not this is actually true. Address the specific instances that made you upset. Offer accurate examples. Avoid statements like "I hate how you lie all the time." Frame your statement like "I felt upset when you lied to me about being too busy to talk yesterday. You lied about that last week too." Open up about how much her actions hurt you and try to let her feel your emotions. Take care not to let yourself get angry or aggressive.  Speak slowly and deliberately. If you find yourself starting to cry, take a moment to gather yourself. If you break down completely and find it impossible to talk, you may need to take more time to compose yourself before continuing. You may be able to reach to her conscience by asking her to see the situation from your position. Ask her how she might have felt if your positions were reversed. Be compassionate when attempting to guide her into seeing the situation from your perspective.

TL;DR in Indonesian:
Bersikaplah tegas dan hadapi dia secara langsung. Pilihlah kata-kata Anda dengan hati-hati. Hindari generalisasi. Tekankan rasa sakit yang Anda rasakan. Buatlah dia menempatkan diri di posisi Anda.