Firstly locate the inbound port on your Ethernet Cable Splitter. Now plug in one end of the Ethernet cable into the inbound port on the Ethernet splitter.
Now locate the outbound port on your modem. Insert the other end of the same cable into this port of the modem.
Next locate the WAN port on your computer. Now take the second Ethernet cable and insert it into the WAN port of your computer.
Last of all, insert the other end of this second cable into the outbound port of your Ethernet cable splitter. The Ethernet cable has now been splitted up into two.