Apple ipod

How to install iPhone OS 4.0 Beta?

I can develop applications as a hobby, but has not received a payment on account Des. So I had OS IPSW file from my cousin, who appears to have downloaded from another site. I try to install it using the Alt + click, then select the file, but my ipod is in recovery iTunes and then says "preparing iPod for restore", then it comes up with an error. How I can run?

Connect your iPod in. Hold Alt and click Check for Updates. Then select the download file. Ipsw. Now updated. If someone wants to be added to my account dev please write me. dlmiddlecote@yahoo.com

JailBreak Iphone 4.0 Beta And How to install Installous on your iPhone iPod Touch