How can I record something off the internet and make it into a ringtone?

Let me explain what I'm trying to do. I'm a big fan of the movie Total Recall with Arnold Schwarzenegger, the original one of course! The one that came out in 1990. Anyway, I found the YouTube video of the "Rekall" commercial Arnold saw in the subway. Is there a way I can record the last 10-15 seconds of that video and save the audio part of it to use for my ringtone on my iPhone? I want it to start at the part where the lady starts singing: "For the memory of a lifetime… Rekall! Rekall! Rekall!" I want just that part and nothing else.
Incidentally I'm not very tech savvy so no wise *** answers like "just record it and save as ringtone!" I want someone that will take the time to explain step-by-step how I can do this.

Download the video as audio from Youtube using Ummyvideodownloader, choose mp3 as format. Once you already have the audio, you can cut it to using Audio Trimmer.

Step 1. Use the screen recorder or audio recorder.
Step 2: use a video converter to convert video to audio or convert audio from one format to another format.
Step import the ringtone to your iPhone or Android devices.

Use Google