The following steps should be followed to open a GIT repository within Simplicity Studio V4:
1. Install Simplicity Studio V4 here - http://www.silabs.com/products/development-tools/software/simplicity-studio
2. Within Simplicity Studio, navigate to Help >> Update Software
3. In the Package Manager window, navigate to the Tools tab. The link to install the EPP Marketplace Client will be found here.
4. Install EPP Marketplace Client and once the installation is complete, restart Simplicity Studio for the changes to take effect.
5. Once Simplicity Studio has started again, navigate to Help >> Eclipse Marketplace
6. In the window that opens, search for egit in the Find search bar
7. Install EGit - Git Team Provider 4.5.0. Leave the default selections and click Confirm
8. Accept the terms and conditions and click Finish. This will start the installation process.
9. After the installation, restart Simplicity Studio for the changes to take effect.
10. Use the Ctrl+3 shortcut to open the Shortcuts Window. Type git in the window.
10. Click on Git in the Perspectives section. This opens up the Git Perspective in Simplicity Studio.
Information about Cloning a Git Repository can be found in this KB article.