To move a buddy from one buddy group to another, perform the following steps:
Select contact that you want to move.
Select the Properties option from the context menu.
The Properties window appears. The Buddy Groups area shows a list of all the groups that you have created. The check box is selected for each group that the buddy belongs to.
Deselect the check box corresponding to the group of your buddy and select the check box corresponding to the group you want to place the buddy in.
Click Save.