Default X10mini broken power button

Hello!

So i have this old Sony xperia x10mini, and i started using this phone a week ago when my lumia 800 died (great phone btw).

The Sony is starting to get a bit old, and so is the android version! so i thought i wanted to try and spice it all up, with a custom rom, to be more specific the MiniCM10. So i managed to root the phone, though it took quite some time. And now i wanted to try and flash the new ROM, but my problem is that to go into the bootloader i need to use the powerbottun, which is broken. So does anyone know a way to get into the bootloader, and navigate around, without using the powerbotton. Or is there no other way?

When i try and use "adb reboot bootloader", it just keeps rebooting...

I do hope some of all the smart guys out there can help me!