You can remove attendees from a to-do of the Meeting type after you have created it using the Create To-do wizard.
You can only remove attendees from an organizer's to-do.
Open the Salesperson/Purchaser Card window.
Select the salesperson who organized the to-do that you want to remove the attendee(s) from, and click OK.
On the Salesperson/Purchaser card, click Salesperson, To-dos.
In the To-do List window, select the to-do that you want to remove the attendee(s) from.
Click To-do, Attendee Scheduling.
Select the attendee that you want to remove, click Delete or press F4 and click Yes.
You cannot delete a to-do organizer.
Editing Attachments to Meeting Invitations