Use This to Download Your OS (Q10, Z10, Z30, etc)
http://forums.crackberry.com/bb10-leaked-beta-os-f395/lengend-presents-10-2-1-1925-all-q-z-887047/
Backup Source
http://www.bbin.in/en/2013/12/24/leaked-os-10-2-1-1925-for-all-blackberry-10-smartphones/
Here are the steps to install a leaked OS on your BlackBerry 10 device (most popular desktop OS required):
Download and install BlackBerry Link (latest is 1.2.2.13 b122) direct from BB.
Backup your BB, just in case and to downgrade if you need to.
Download correct OS from CB URL link above (don't worry about the term "radio" - from the one that says "10.2.1.1925").
Switch off your BlackBerry 10 device
Run the AutoLoader File
Connect your BlackBerry 10 Device to your PC via USB
Quickly Turn on your BlackBerry 10 device
The AutoLoader will detect your device and starts the installation
Please hold till the AutoLoader reaches to 100% and CLOSES automatically
Disconnect your BlackBerry 10 device and wait till it starts again
Security wipe before start using/restoring your data (I didn't do this, but the instructions suggest it)
Manual Setup your config, apps, etc
Enable the install apps functionality from 3rd parties. The first time you download and run an app, the OS will prompt you to enable this feature. Thanks BlackBerry!
Bonus: 2 good sources for loading Android apps is Amazon Apps and 1mobile.com. Load both App Store Apps and you can load your new Android apps easily.
Screenshots of the goodness (note: no BES required, but I run one since I roll like that)....
Before
After - 10.2.1.1925 (yeah baby)
To a Happy, Healthy, Productive, and Efficient 2014!
-Ben