How to install new custom firmware?

[annddrrewww]

I currently have a iPhone 4 running on AT&T that is tethered, running 4.3.5(8L1) and firmware 4.10.01.
I first off want to unlock it. I also want to upgrade my iPhone to iOS 5.0.1. Would it be safe, how would I do it if it is safe? Is there an unlock available? Thank you for the help.

[xtacy]

There is gevey sim available for unlock. But it works only on the basebands upto 4.10.01 . Seeing that you already have it you should make a custom firmware using sn0wbreeze if u on windows or pwnagetool if u on Mac and then update to 5.0.1 so as to preserve the baseband and keep ur phone unlocked. :-)