Bend your chest open so I can reach your heart. I need to get inside or I'll start a war.. this is a woman who is completely frustrated with a man she has strong feelings for because he is keeping his distance. She is pleading with him to let her into into his inner most being. Something he is very cold and calculated about guarding from anyone. His emotions. Clearly life has not been kind to him and he has been hurt by others in the past to make him build up walls and to live in an ivory Tower. The war she will start will be an argument or even mind games because she is frustrated by the fact that she is giving him her love her emotions her heart and he won't let her into his. It is clearly an unequal playing field of love.

She wants to build him up and pick him apart. No I know some people would think that picking A Man apart means to be little then but that's not what she means here she starts off by saying she wants to build him up and her own mind and heart she already has she wants him to know just how much she admires him adores him thinks the world of him!!
The pick you apart is piece by piece all the little things he's afraid to share with her it is so that they can grow in their relationship to a more intimate level of passion and security.
And yes is everyone else had already said she wants to see the dark side of him as well. Was all consumed with him he need not worry that he exposed himself completely to her the darkness and the light she already loved she just wanted him to love her back as much and and not be afraid to be completely naked and exposed in front of her.

This is by far one of THE MOST touching loves songs that can make me shake and cry with such emotion no matter how many times I listen to it.

As each new scale that he reveals that he rips from himself is laid bear at her feet she collects them and stores them in her own heart. He is literally now a part of her.