The problem: All the buttons on my phone are broken. Replacing them is only a temporary solution since my back cover is broken and I can't find anywhere a replacement that does not exceed the price of a used OPO, but I figured why not upgrade if I am going to buy a phone, which I will do in a few months when money won't be as tight.
My solution is basically multiple smaller solutions
Volume controls: Vol- and Vol+ on the on-screen NavBar.
Screen on and off: Using a ROM that supports double tap to wake/sleep.
Restart: There is an app for that (multiple actually)
This worked for a few weeks but today my phone turned off for no apparent reason and I had no way of turning it on until I got home 8 hours later, so I decided to do something about it, instead of needing a screw driver every time I need to power it up.
Step 1: Soldering
ATTENTION: TURN OFF THE PHONE AND DISCONNECT THE BATTERY FROM THE PCB
USE AT YOUR OWN RISK, I AM NOT RESPONSIBLE FOR BRICKED PHONES
First I started by soldering 2 pieces of thin wire to the power button connectors on the PCB, I used some Cat5e I had laying arround.
Step 2: Routing and Taping
Then I routed the cables around the spacing of the battery and the case, making sure that I am not shorting anything with it, pay extra care to the battery connector since that thing could deliver a lot of power. I used Aluminium tape to tape the wire strands on top of the battery so it can be accessed easily by removing the back cover, but any conductive tape will do.
Putting the phone back together and testing it.
Perhaps a better solution would/could be getting a flex PCB button instead and taping that on the back of the phone, but I could't wait the amount of time for it to be shipped, I need my phone.
Now to people wondering how did I F' up my back cover so much, it was a combination of half assing the NFC+Qi Charging mod by not grounding away some of the back cover and repeatedly dropping the phone from within my pockets.