How to downgrade an iPhone to iOS 5 on a PC?

I just started using my brother's old iphone 4 as an ipod touch (I already have a phone and was previously using a 3rd gen ipod touch), and I want to reverse my mistake of downloading ios6. I'd rather keep using this iphone than go back to my old ipod which still has ios5 because of the crisper screen and the camera. The only cool features of ios6 that work on an iphone 4, such as turn by turn navigation, don't apply to me because I can only connect to the internet with Wi-Fi, so don't tell me it's worth the setbacks to keep the new OS.

My main problem with ios6 is how it affects youtube. I already used google's youtube app before I downloaded ios6, and I liked the improvements it made to the old default app. Now, the youtube app automatically adjusts the quality of the video based on your internet connection in ios6. This means half the time the video loads at extremely low quality, both audio and visual, yet before I downloaded the new ios it was always high quality. This is a deal breaker for me because I'm only using this device for music and videos.

I looked up how to download ios5 already, and kept getting directed to this link http://www.maclife.com/article/howtos/how_downgrade_back_ios_5. This doesn't help me because I have a pc, and the instructions are for a mac. When I got to step 3, I couldn't figure out how to get to the "Finder File", because there's no option key on pc keyboards. I tried the alt and ctrl keys with no luck.

So how can I downgrade to ios5 using a pc? I already have the ios5 file from the above link, I just need to get it onto the iphone.

Unfortunately, as far as I know it, that mistake is not reversible without hacking it in some way, like jail-breaking it.