Sony XBR-55X850D Service Manual page 197

How to disassemble HEAT SINK (DPS board)
HOLDER, HS WS (MUF)
4-548-743-01
HEAT SINK (MUFF)
HOLDER, (HS MUF)
4-549-188-01
XBR-55X850D/855D/857D, 65X850D/855D/857D, 75X850D/855D/857D
<NOTE>
HEAT SINK are already attached to the DPS board for service.
If you need to disassemble HEAT SINK from DSP board for repair,
Please cut HOLDER,HS WS(MUF)
However, please do it carefully because some damage may be given
to the neighborhood parts or the DPS board itself.
When you re-assemble HEAT SINK,
Do not reuse HOLDER,HS WS. Should be replaced to new parts.
And Potting operation is necessary
Please refer SBR "New Potting TIM Operation for board repair" for details.
Push
Unhook HOLDER,(HS MUF)
Do not reuse HOLDER.
Should be replaced to new parts.
with tool (nippers) from B side of DPS board.
at the same time for re-assembly of HEAT SINK.
APPENDIX-2
nipper
197