As can be seen in the following pictures, the eReader will not fit into the Nintendo DS due to the way the linkport connector is arranged, for the original Gameboy advance system. You will need the following tools to disassemble and modify the eReader.
Tri-Wing driver (It is also possible to use a precision slotted driver to remove the screws)
#0 philips driver (Again, a precision slotted driver can be used here.)
Some form of cutting tool. (xacto knife, rotary tool) (only if you need the eReader link port connector for the original gameboy advance.)