Keypress Speed Dial lock.......

Does anyone know how to unlock a keypress speed dial lock on the Q10 (phone, swipe down, settings, keypress speed dial).....
My W key, normally assigned to Voicemail, somehow got assigned to my doctor's number.....
Not sure how this happened, but when I go to reassign the W key, there's a small lock that shows up to the right of my docs number that won't let me change the assignment.....for the life of me, I can't figure out how to reassign the W key back to Voicemail (T-Mobile). Any suggestions would be greatly appreciated.
Thanks,
RF

Tap the phone icon on the bottom left of your screen or open up the dial pad. Then swipe down from the top of the next window and you'll see settings.... tap it and all the options for Call Forwarding, waiting, blocking, fixed, smart, speed and so on will appear! You can't get to it through the regular settings.

Also, the main HELP icon will tell you and show you everything you ever wanted to know about your device and the present OS installed!

OK! Just realized you have a Q10. I have a Z10...

Give it a shot. I'm sure someone will come around during more normal hours to lend you a hand!