As a Nigerian Living in the 21st Century, you'll understand when i say we're all chaser of good things. If you want to upgrade your BB OS, you will need to follow a few steps and gather a few items. First, you need a Windows-based PC, a USB cable for your phone and the correct OS downloaded from the forums. The OS will be in the form of .exe. (Note to Mac users: you need a bootcamp partition on your Mac in order to use the Mac OS.)
NOTE ON DEVICE MODELS:
All Z10 variants (STL100-2, -3, -4) are the same EXCEPT for STL100-1.
All Z30 variants (STA100-x) are the same.
All Q5 (SQR100-x) and Q10 (SQN100-x) variants are the same.
First Things First:
Now, before any install it is always wise to make a backup of your device . (Backup by plugging to BlackBerry Link and choosing backup. It takes a while. Leave the phone alone till your phone backup has completed.) A backup is going to be useful if you want to restore everything once you load the OS. A backup is never a bad thing. There are situations where you probably shouldn't restore, but we will discuss those later.
Finding Your OS:
To start, you will need to confirm your device model number. You can find this information by going into your 'About' menu within the settings. If you have a Z30 it will start with STA, Z10 with STL, a Q10 with SQN, and a Q5 with SQR.
Once you know your device model number, you need to follow this link in order to see the list of Leaked OS available for download BB10 Leaked/Beta OS.
From that link you will see many different OSes represented. You need to determine which is the version number you want to run on your device and then download the file. MATCH the number of your device to the correct number on the OS file.
More than likely, the file will be hosted at MEGA or bitcasa and you will need to wait about 15 minutes for it to completely download. When it downloads, the file will be in a RAR format. You may UNZIP the file using WinRar or 7Zip. REMEMBER: your goal is to get to an .exe file.
Loading the OS:
Once the file has downloaded, make sure BB Link is CLOSED. Plug your phone into your Windows PC and double click the .exe file you have just downloaded. The AUTOLOADER will start installing files to your phone. During this process it reboots your phone as well. DO NOT TOUCH YOUR PHONE WHILE THIS IS GOING ON. You run the risk of soft-bricking your device (black screen red blinking led) if you fiddle with your phone during the loading process. Do not touch the phone.
In about 10 minutes, the OS will load. and the phone will reboot. When it reboots, it will bring you to the initial setup. There are questions you must answer and initial swiping you need to do. Do it. Put in your BBID when asked. The phone will boot to the home screen.
Restoring Your Backup:
At this point you may restore your backup if you would like. Restoring a backup is not recommended if you were having overheating problems or severe battery draining issues on your phone prior to the OS upgrade. Sometimes restoring the backup only adds those same problems to your new install.
If you DO want to restore, plug your phone into your PC and open BB Link. Choose restore and then the latest file (backup) that you made. The process begins. Depending on the data on your phone, the process could take as long as 1 hour. Do not try to use your phone during this process either. Leave it still and plugged into your PC.
After following these steps, you should have successfully loaded a new OS to your Baby BlackBerry!
Changes and suggestions to this guide are welcomed. Please PM me.