TestMonitor allows you to batch-edit milestones.
In the milestones overview, move your cursor over a milestone and tick the checkbox on the left. Select additional milestones or select them all by ticking the checkbox in the table header.
Next, click on the green multi-select button in the toolbar and select a batch action.
The batch-edit function for milestones offers the following actions:
Choose Delete and you can delete all the selected milestones from your project.