On the nav bar, click the Activities menu, then select Checklist.
Click the context menu to the right of the checklist you’d like to edit, then select Edit,
Under Categories and Items, check the boxes to select the items you wish to delete. To select all categories & items, check the box at the top of the table. Note: Selecting Categories will select all items within the category. Then, Click Delete.
A confirmation message will display. Click Delete.