How to downgrade iPhone 5 from ios7.1 to ios 7?

I have an iPhone 5 and recently, I accidentally performed the latest ios update. In doing so, I lost my jailbreak. I'm desperate to downgrade from the latest ios firmware to ios7. I have used software called iFaith, which gives detailed instructions on how to do this. I have followed the instructions time and time again. Download iFaith from the above link and start it.

STEP 2: Click on "Build "*signed* IPSW w / Blobs".

iFaith version

STEP 3: Now select your SHSH blobs followed by the firmware file you want to downgrade to. IFaith will create a custom IPSW file.

STEP 4: Now you will be required to enter in to DFU mode. If you know how to do that, go ahead and do it now but if you don't then follow the steps below.

Hold Power + Home button for 10 seconds.

Release Power button but keep holding the home button for another 5 seconds.

You will have entered into DFU mode.

STEP 5: Now fire up iTunes, make sure its iTunes 11.0.5 or below. Once in iTunes, select your iPhone and hold down "Shift button" and click on the "Restore iPhone". A pop-up box will appear, here you will have to browse for your custom IPSW that iFaith has created in STHowever, when I look for the ios file that I previously downloaded, to downgrade, it does not appear anywhere. Yet, when I open "Documents" on my PC, it is there. But with the iFaith software, when the "Documents" window appears, the file can't be found.
I would very much appreciate any advice on what I might be doing wrong

There's NO way to downgrade iPhone 5 or any device to IOS 7.0x.

iFaith's last use was to downgrade an iPhone 4 from IOS 7 to IOS 6.1x
Here is an actual guide that explains how you could do it IF you had iPhone 4.
http://www.redmondpie.com/how-to-downgrade-ios-7-to-ios-6-6.1.3-6.1.2-tutorial/

Stupid people like to paraphrase that guide, or similar guides, and leave out the iPhone 4 ONLY part of it. The iP4 exploit was hardware based and won't work on a A5 or newer processor.