How to return a faulty machine

I am in the UK but ordered a laptop for my nephew in Alabama in December. It worked fine for a month then on Saturday, he went to power it on and nothing happens. The light on the power supply is on. I told him to try a hard power down by holding the power button for 20 seconds. Still nothing happens.

I assume it is faulty and needs to be repaired and it is still under warranty. I have looked and looked but I cannot find any way to return it via the Dell website. While searching, I did see the form to be printed off and enclosed with a return but no return address or instructions beyond how to package it up.

I have bought 7 or 8 Dell laptop over the years and they are fine when they work. However, it seems the return process is totally opaque/obfuscated. Can anyone tell me what to do?

Thank-you.

Julius