Click Edit > Explode All to break up objects into their individual segments. For example, exploding a rectangle will produce four individual lines which can then be edited separately.

Have the desired design on the screen.

Click Edit > Explode All.

The objects in the current design are broken down into their individual segments which can then be edited individually. 

For an example, select and delete the desired arc.

The selected arc is deleted.

You can further edit the design and add other elements.

Manually explode selected objects with the Explode Circuit button.

This allows you to manually select which objects to explode.

Use the Explode All button to explode the current project.

The objects in the current project will be exploded into their individual segments.