If you have keep the automatic update enabled, it should be automatically updated.
You can also download it from the below links:
- x64 version https://go.microsoft.com/fwlink/?LinkId=828603
- x86 version https://go.microsoft.com/fwlink/?LinkId=828604
It is important to note that this version adds support for SHA-2 code signing support which will be required by May 18, 2020.
If you are running the Monitoring Agent on ‘legacy’ OS version (Windows 7, 2008, 2008 R2 – which I remind you are out of support unless running on Azure), you will need to apply the documented actions here https://docs.microsoft.com/en-us/azure/azure-monitor/platform/log-analytics-agent#sha-2-code-signing-support-requirement-for-windows