Before inserting the new EPROM, notice that the EPROM has a small groove in one end; the end with the groove in it must match the groove in the socket which it is to be inserted into. Don't insert the chip backwards -- line up the groove in the chip to be on the same side as the socket's groove.
You may need to slightly bend into the center the legs of the EPROM so that they can be inserted into the socket. Place the chip into the socket and begin to lightly push the chip into the socket. Unless you check, you may bend one of the leads not in a hole underneath the chip -- making your Reader disfunctional. Once you are sure all legs are positioned into the holes correctly, you can push hard until the chip is firmly positioned into the socket.
After turning the re-powering the WDP by plugging back in the "Y-Cable", you should hear 3 beeps. This indicates that the EPROM has been successfully installed. If it doesn't beep three times, immediately unplug the "Y-Cable" and remove the EPROM and check for bent legs. Also be certain you have not placed it in upside down, (not matching the notches). If you have placed it upside down and were a little slow in removing power, you probably have burnt out the EPROM and will have to replace it before proceeding.