To expand upon what the Codemonkey said in the other guide, you're going to want to collect at least 2-3 holodiscs / audio tapes and then leave Rivet City. He did a simple version of the whole thing, which doesn't include the complications with who you talk to and what you find out... There are a variety of ways to complete the quest, and just a few minor details were left out I thought people would like to know.
Here is what I did:
-Spoke with Dr. Zimmer
-Went to the Rivet City clinic to speak to Dr. Preston to get the first audio tape
-Went to the Rivet City marketplace to speak with Seagrave Holmes and received an audio tape (in a speech challenge, so save before talking!)
-Left Rivet City and waited about 10 seconds
-Victoria Watts approached me and gave me the android part
-I went to Dr. Zimmer, gave it to him (in a lie) and completed the quest.