Strange, those buttons should be non-functional during combat.
To remove, search this text and replace with nothing:
Code:
<Button LocalTooltip="Leave Group" Location="105,6" Name="Leave" OnHoverIn="Opacity=1.000" OnHoverOut="Opacity=0.000" OnPress="Leave" Opacity="0.000" ScrollExtent="16,16" Size="16,16" Style="/WindowElements.WindowFrame.data.close.style" Tooltip="Leave Group"></Button>
Code:
<Button LocalTooltip="Kick" Location="105,6" MouseOverTextColor="#FF0000" Name="Kick" NormalTextColor="#FFFFFF" OnHoverIn="Opacity=1.000" OnHoverOut="Opacity=0.000" OnPress="kickfromgroup" Opacity="0.000" ScrollExtent="16,16" Size="16,16" Style="/WindowElements.WindowFrame.data.close.style" Tooltip="Kick"></Button>