Eclipse based Code Composer Studio: Downgrade Compiler Tools
The CodeComposer Studio update assistant rejects installing old tools, if a new tools version is installed:
"C6000 Compiler Tools" will be ignored because a newer version is already installed.
2.1 Uninstall and delete latest compiler
Make sure the just uninstalled compiler is deleted from your tools folder, else the CCS will scan this directory during the next start and add this compiler again to your available compiler tools list.
2.2 Install older compiler tools
Select "Install New Software..." or "Install Code Generation Compiler Tools..." depending on what is available in your CCS installation.
Choose the older compiler tools you whish to install:
2.3 Verify installation of older compiler tools