How to downgrade a iPhone 4s from ios 7.0.4 to 6.1.3?

I have the correct shsh blobs saved to downgrade, but can't seem to find a definite answer as to whether it is possible to downgrade an iPhone 4s or any a5+ idevice.

Don't know

You can't downgrade an iPhone, but you can make it look like an ios6 version by jailbreaking. So if you downgrade, your jailbreaking your iPhone. By the way, you lose your warranty if you jailbreak, and if you don't get the jailbreak right, you may not ever see your phone turned on again. So get the safe jailbreak and do it right.