BlackBerry Q10

Find "Phone"

Slide your finger downwards starting from the top edge of the display.
Press Notifications.

Find "Phone"

Press Phone.

Turn on the ring tone

Press the indicator next to "Sound" until the function is turned on.

Select your ring tone

Press Tone.

Select your ring tone

To use one of your phone's default ring tones:
Press the different ring tones to listen to them.

Select your ring tone

To use one of your own ring tones:
Press Browse Music....

Select your ring tone

Go to the required folder.
Press the different ring tones to listen to them.

Select your ring tone

Once you've found a ring tone you like, press the return icon.

Return to the home screen

Slide your finger upwards starting from the bottom edge of the display to return to the home screen.