How to straighten a bent Redmi phone?

The biggest problem with trying to straighten a bent frame is the fact that it's glued to the screen, which does not bend. Trying to straighten bent metal with the screen still attached runs a very real risk of cracking the glass, at which point you will not only have a bent frame, but a broken screen as well.

I see two approaches available to you. First, you could try and straighten the midframe, but I would not suggest doing so without removing the screen first. There's a YouTube video showing the process, but my only criticism of it is that they are replacing the screen so the author doesn't care about destroying the old screen in the process of removing it. Assuming your screen isn't damaged, you'll have to be a lot more careful removing it than the video shows. Be aware that with a bent frame the glass may be under tension and could be more susceptible to breaking than it would be ordinarily.

REDMI 13c LCD Replacement - YouTube

I'd suggest following the guide to get the screen off, then use a straight-edge to determine exactly where the bend is. Straighten it as best you can then recheck with your straight-edge. Repeat that process until it's as close to perfectly flat as you can get it, after which you can test fit the screen to ensure it sits correctly in the frame.

Personally, if it was my phone, I would go ahead and replace the midframe. They generally aren't expensive, but of course it will be more work than just trying to straighten the screen. On your phone, like many Android phones, the recommended way to replace a screen is by purchasing a screen that's already mounted to the midframe. Replacement then becomes a matter of removing all of the internal components of the phone and transferring them to the new screen+frame assembly. I mention this for two reasons; first, should your screen break in the process of removing it, you would be able to solve both problems at the same time by using this method to replace the screen.

Secondly, assuming you're able to successfully remove the screen, this would give you a brand new midframe that would definitely not be bent. To replace the midfame you would need to combine the previous guide with the following one; in other words, you'll follow this guide and remove all of the internal components first as though you were replacing the entire screen+midframe assembly.

xiaomi redmi 13c screen replacement and disassembly using original display - YouTube

Once you have everything out of the phone, go back to the other video and use it to remove the screen. Once it's off, you'll need to glue it to the new midframe, then go back to the second guide and finish the transferring of parts to your refurbished screen+midframe assembly.

Either way it's going to be a bit of work, but these are the best ways to fix your midframe while minimizing the risk of damage to your screen.

Good luck, and let us know how it all turns out! Your experience may help the next person who comes along with the same problem.