To disable the HMAgent on all the agents, create an asset job as below and run it on All Computers.
1. In the DSM Explorer, navigate to 'Asset Jobs'.
2. Right-click and select 'New'.
3. Select the Job Type as 'Command Job'.
4. Give the desired name and description to the job.
5. Add the following commands in the editor:
tasskill /f /im hmagent.exe
sc config hmagent start= disabled
6. In the Next screen click on 'Set Scheduling' and choose 'Run Only Once'.
7. Click Finish.
Once the Job is created you can link it under All Computers->Group Details->Jobs->Asset Jobs.
Note: You can disable the Health Monitoring agent using Software Delivery as well by creating a batch file with the two commands and deploying it to the agents.