If the time or place of your meeting changes, you can only amend the meeting details if you set it up yourself
If you did not set up the meeting, the meeting owner will have to make the changes
Click Calendar in the navigation bar at the top right of the screen
Click on the meeting and select Edit at the bottom of the box that appears on the screen
If you are editing a recurring meeting, you can either choose to edit the occurrence, meaning only the selected occurrence will be changed, or the series, meaning all occurrences of the meeting will be updated
A screen will appear with the current meeting details, where you can change the details in the same way that you created the meeting
When you have finished, click Send at the top of the screen and all attendees will receive an updated invite