If you want to edit an item you have already entered in the forecast (for example, a revenue stream, expense, asset, etc.), just navigate to the correct page of your Forecast tab, and then click on the blue title of the item you'd like to update:
In certain tables, such as the Personnel table, you may need to click the triangle icons to expand the lines so you can access the editable entries, as shown below:
Clicking any blue title will open the editing options for that item. Use the Next and Back buttons to navigate between them, as shown below:
You can edit any part of your entry. Click Save & Close when you're done.
To delete a forecast item you've already entered, follow the same steps as above, and look for the trash can icon in the lower left corner of the first box of editing options: