Acer Aspire T136 Service Manual page 57

Standard Disassembly Process
5-4. Remove the screws shown below and romove the USB board with the bracket.
6. Remove the Power supply.
6-1. Disconnect the ATX power "P1" connector from the Motherboard.
6-2. Disconnect the "12V DC" connector from the Motherboard.
6-3. Remove the four screws shown below then take off the power-supply.