just take your window and delete all the button references and paste this above all
<Button item="BW_Player_Buff_Template">
<ScreenID>Player_Buff_Template</ScreenID>
<RelativePosition>true</RelativePosition>
<Size>
<CX>34</CX>
<CY>34</CY>
</Size>
<Template>BDT_PlayerBuff</Template>
<DecalOffset>
<X>2</X>
<Y>2</Y>
</DecalOffset>
<DecalSize>
<CX>30</CX>
<CY>30</CY>
</DecalSize>
</Button>
<TileLayoutBox item="BW_Buttons">
<ScreenID>Buff_Buttons</ScreenID>
<RelativePosition>true</RelativePosition>
<AutoStretch>true</AutoStretch>
<BottomAnchorToTop>false</BottomAnchorToTop>
<RightAnchorToLeft>false</RightAnchorToLeft>
<Style_Transparent>true</Style_Transparent>
<Spacing>0</Spacing>
<SecondarySpacing>0</SecondarySpacing>
<HorizontalFirst>false</HorizontalFirst>
<AnchorToTop>true</AnchorToTop>
<AnchorToLeft>false</AnchorToLeft>
<FirstPieceTemplate>true</FirstPieceTemplate>
<Pieces>BW_Player_Buff_Template</Pieces>
</TileLayoutBox>
and add this line to the buffwindow section
<Pieces>TileLayoutBox:BW_Buttons</Pieces>
then adjust