Go to the item screen for the subject meeting.

How do I edit an item?

The third tab is the Attachments tab

The Attachments tab has two parts: the list of documents currently attached to the item on the left, and a viewport on the right.

Find the attachment that you want to replace.

Click the green edit attachment button.

Click the Choose a file to upload link.

Choose a file from your computer and click the Update Attachment button.