How to install unsigned ios 10.3

I downloaded the ios 10.3 when it was signed as shown on ipsw.me. And couldnt able to downgrade it from 11 to 1.0.3 at the same time. Was busy in something. But when later on i was downgrading some error 3194 was popping up and apple unsigned that software. So is there anyway i can downgrade that software. I have 10.2.1 and 10.3 signed firmware files. But they aint working anymore. Since apple stopped signing them. Help needed. Need to downgrade