First, you need to install TI's Code Composer Studio. I've successfully tested the setup with CCS version 9.2 and older once. You can find a download link here:

Download CCS

Click for download and ensure you have at least chosen the MSP430 ultra-low-power MCUs while installing. Meanwhile, you can grab the update site for YAKINDU Statechart Tools. Go to:

Download YAKINDU Statechart Tools

On this site, click on Download Now and follow the instructions. As you can see in the photo: It is free for non-commercial use. After the registration, you'll get an overview of the download options. Click on STANDARD DOWNLOAD SITE and click on INSTALL FROM UPDATE SITE. There you'll get a link under Stable Releases. Grab this link and save it or put it in your clipboard.

Installing YAKINDU Statechart Tools into Code Composer Studio can be a little bit tricky, depending on the version of Code Composer Studio you're using. Maybe these steps are outdated meanwhile - however: don't hesitate to ask me in the comments if you need any help.

These are my steps:

After successfully installing CCS to your system, open the Help tab and click on Install New Software... In this wizard, add the following update site via the Add... button:

https://download.eclipse.org/releases/2018-09/

Don't add anything, it just needs to be resolved. You can see it in the picture.

After this, repeat the steps and click on the Add... button. Insert the YAKINDU Statechart Tools update site, which you've hopefully saved. Then, select the YAKINDU License Management checkbox and click on next. Follow the instructions. Your IDE may restart once.

Finally, you can install YAKINDU Statechart tools. Repeat the last steps, but this time choose YAKINDU Statechart Tools Standard Edition. Once again, follow the instructions. After restarting you have successfully installed YAKINDU Statechart Tools.