After a meeting is created you can always change the meeting location.

Go to the meeting screen for the subject meeting.

How do I edit a meeting?

On the left side of the screen, find the Meeting Data block.

Find the meeting location. If your access privileges allow you to change the location of the meeting, a Change Meeting Location link appears below the location.

Click the link to display a text editor

Enter the new location and click the Update Meeting Location button.