Add size to Parts list, in the design workspace:

• Right-click one or multiple components and select Link Size/Description. The size in the component's description will stay updated from now on.
• Create a drawing and place a table: the component size will be shown as the component's description.

Remove link (and remove dimensions from description):

• Right-click one or multiple components with a linked dimension; select Link Size/Description. 

Note that Assemblies cannot be linked to their size. (If necessary, get in touch with the developer!)

Install:

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. 

Uninstall:

You can unload the add-in without uninstalling it by clicking the "Stop" button when the add-in is selected in the list box on the "Add-Ins" tab of the "Scripts and Add-Ins" dialog.

Unchecking "Run on Startup" causes the add-in not to be loaded in future sessions of Autodesk® Fusion 360®.

To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. 

OR, you can uninstall it from 'Control Panel/Programs and Features' (Windows 7/8.1/10), just as you would uninstall any other application from your system.

Manually changing the size in the description text will prevent the add-on from recognizing it as the previous dimension; on the update, new dimensions will be added instead of replacing the old dimensions.