Explain like I'm 5, how do I upgrade my unaltered Atrix to Android 4.0+?

[AmantisAsoko]

All the guides say different things, EVERY link is dead, everything is outdated. It's all VERY confusing. Is there a modern guide with working links and downloads anywhere? I just need any android above 4.0 for a certian app.

 

[ravilov]

Install AtrICS 2.0 or ICSROM.
All relevant links and instructions are included in each respective thread.