remember, these things are a ways off. focus on the change itself first.
When/if she does initiate contact how do I show her i have changed?
you simply be safe, warm, inviting, light, upbeat, confident. its a subtle thing. you dont "show her youve changed" in one conversation, you just leave her feeling good about it and wanting more.
What do you mean by pit myself in front of her?
i dont mean it literally. what i mean is if you havent heard from her in another month or two (i would expect it to take about that long... .ive been in your situation, and finally heard from an ex after about three months) and you are still interested, you will need to do something. what that "something" is will very much depend. it could take the form of a direct or indirect reach out.
Meili mentioned social media. are the two of you friends on facebook? i dont know much about whatsapp, is it a format in which you can post pictures or share updates on your life or just a messenger?