While we have an extensive, detailed guide on how-to sideload Google Play Store client Snap onto your BlackBerry 10 device, the dev named WeirdTurtleMan has created a simple Windows version app of a previous installer that makes it easy to install Snap with one click.
Basically you plug in your device via USB to your computer and press the install button, it’ll do all the work.
Download SnapLoad here
There is a readme guide that the dev put into the zip folder but I list them out here:
Please follow these steps before you start:
1. Connect your BlackBerry device to the computer via USB
2. On your device go to Settings
3. Go to Security and Privacy and then Development Mode
4. Enable Development Mode
5. Set a Device Password
6. Remember the IP address