Samsung Galaxy S8 Disassembly & Assembly Manual page 18

Disassembly - Back Glass (5/8)
5) Gently rotate the handle of OCTA disassembly upper.
6) When the back glass starts to be detached, carefully rotate handle
with watching the back glass status.
[ Note ]
Do not use the ethyl alcohol to disassemble back-glass.
(except for battery swelling case)
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