Here's a tutorial on how to downgrade iOS 10.3.2 to iOS 10.3.1 running on iPhone, iPad or iPod touch right away.
Apple is Currently Signing iOS 10.3.1 - Downgrade iOS 10.3.2 Today if You So Wish
Apple released iOS 10.3.2 download for iPhone, iPad and iPod touch users a while back. If, for some reason, you believe that upgrading to the latest firmware version was a mistake on your end, then you will be pleased to learn that you can downgrade back to the older iOS 10.3.1 firmware right away. But keep one thing in mind: this process applies for a small period of time. Basically, up until the point where Apple is signing the older firmware. Once it has closed the signing window, you are stuck on the latest firmware for good.
Tutorial
Performing a downgrade will erase everything off your device, so make sure you have everything backed up in a safe and secure location.
1. First of all, make sure you disable Find My iPhone and download the iOS 10.3.1 firmware file for your iPhone, iPad or iPod touch.
2. Connect your iOS device to your computer using a USB cable and launch iTunes. If you haven't downloaded iTunes already, then head over to: apple.com/itunes
3. Once iTunes is all loaded up, you'll see your device listed on the top left hand corner of iTunes. Click on it.
4. Assuming you have downloaded the iOS 10.3.1 firmware file on your computer, hold down the left SHIFT key (Windows) or the left OPTION key (Mac) and then click on the Restore iPhone button in iTunes.
5. At this point, just select the iOS 10.3.1 firmware file and the downgrade iOS 10.3.2 will begin immediately.
iTunes will first of all extract the firmware file, then restore your device, ultimately verifying the installation with Apple itself. Once that is done, you will be presented with the iOS welcome screen. From there, just sign in with your Apple ID and you are golden.
Quite frankly, I don't see why anyone would want to downgrade to an older firmware version at this point. Small updates like the one released today tend to keep things running smoothly over a period of time. But still, you might have your own reasons for doing so.
