Text on Arc add-in creates sketch text on the selected arc, spline, elliptical arc, conical curve, circle, ellipse or line. This add-in allows you to specify the arc, text, font name, font height, font style, alignment, spacing, offset, kerning and side of the arc. It has an option to break the text into profiles and an option to edit an existing text on arc.

Steps to create new text:

1. Open a sketch.
2. Draw a sketch arc, spline, elliptical arc, conical curve or line.
3. Press the "Text on Arc" button in the "Sketch" panel.
4. Select the arc.
5. Enter the text, height, font name, style, alignment, spacing, and offset.
6. Select the "Flip" field to create the text on the other side of the arc.
7. Select the "Explode Text" field to break the text into profiles.
8. Press "OK" button.

Steps to edit existing text on arc:

1. Open a sketch.
2. Press the "Text on Arc" button in the "Sketch" panel.
3. Select the existing text on arc created with the "Text on Arc" add-in.
4. Change the text, height, font name or style.
5. Press "OK" button.

Install:

1. Download the installer from Autodesk App Store.

2. Right-click on the "Downloads" folder and select "Open in Finder".

3. Right-click on the "TextOnArc.bundle-macos.pkg" -> "Open With" -> "Installer". 

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™.

- Navigate to ./ApplicationsPlugins folder and select the app bundle you want to uninstall

- Either drag the app bundle to the Trash, or right-click and select “Move to Trash”

- Right-click on the Trash-Can and select “Empty Trash”

- If you prefer keystrokes, you can also just select the app bundle and then hit Command+Delete to move the app to Trash, then empty the Trash and the app will be removed.