Once you have the Overlayed_<version>_x64_en-US.msi
you can then open it to being the install process.
Once you open the .msi
file you will be greeted with an installer window, follow the steps to complete the installation.
Because Overlayed has not built trust with Microsoft you might see a smartscreen warning. You can click More info
and then Run anyway
to continue with the installation.
You now have Overlayed and you can follow the steps provided in the app to get started!