To change Activity Monitor from its default icon, first make sure the utility is running. ... If you quit and relaunch Activity Monitor, the software remembers the chart you selected most recently.

With the app open, go to the Dock and right-click on the Activity Monitor icon. 2. In the pop-up menu, move the cursor to Dock Icon. 3. Another pop-up menu appears with the monitors you can select.

Now, click and hold on the Activity Monitor icon in the Dock, and select "Hide" to remove the window from your Mac screen. Next, press the Control and Option keys and then click and hold on the ...