How to edit or install the framework file in Xcode via Carthage?

How can I edit or install the framework swift file in Xcode via Carthage?

In this screenshot only have 2 file, Why? How to install the swift file in it? So that I can modify it.

What I want to do is change some code in PieChartRenderer.swift. What I want to modify: Here is the link

File location: Carthage > Checkout > Charts > Source > Charts > Renderer > PieChartRenderer.swift

I followed Usage on the README.md. I have completed this 4 step.

1. Drag the Charts.xcodeproj to your project
2. Go to your target's settings, hit the "+" under the "Embedded Binaries" section, and select the Charts.framework
3. @import Charts
4. • (Xcode 8.2+) Under "Build Options", mark "Always Embed Swift Standard Libraries"

Current problem: I Dragged the Charts.xcodeproj from Checkout to my project. The code is work when I run it on stimulator. But when I stop it and open it again, the value line show up again. On real device, the modified code is no effect... Why?

Sorry, I'm new in Carthage.