Can someone please outline the procedure to go from 4.3.2 to 4.2.1

[iluvifone]

I am currently on an iPhone 4 (not verizon) on 4.3.2. I have all my SHSH's saved, and I want to go back to 4.2.1.

Can someone give me a quick step by step guide.. here's what I tried, but it failed..

1) turn iphone off
2) put in DFU
3) open tiny umbrella, iphone isn't recognized since it's in DFU, so i just hit "start tss server"
4) open itunes, shift+click and selected the 4.2.1 image. I keep getting error 1601.

what am i doing wrong?

 

[maclaptop]

Easy. Go to Apple support online its explained cleary there.

 

[iluvifone]

Easy. Go to Apple support online its explained cleary there.

apple doesn't want you going back to an old firmware, as far as i'm aware. prove me wrong though with a link