You are hereToshiba U400 Laptop Harddisk and Memory Replacement Guide / Memory Replacement
The memory plate is held together by three Philiphs screws. Lets get it off.
Unscrew all three screws and use the tag to lift off the memory plate.
Once the plate is off you can see the memory modules and the wireless LAN card.
Mind you the LAN card is connected by wires to the other side of the memory slot. So don't be too enthusiastic about taking it out.