Edit Diameter Dimension
Select the dimension, and the Edit Dimension tool will launch.
Click on the first point of the entity to move it to a new position along the circumference. Click to confirm the location.
OR
Click on the end vertex of the Witness line to change its length.
Click on the canvas to place the Witness line.
The dimension text of the selected dimension will be displayed accordingly, and you can position the text to either left inside, left outside, right inside, or right outside.
Right-click and select Confirm, click on the check mark in the sidebar, or press Enter to commit the change.
Press Esc to cancel and close the tool.