Renaming Name of Keyboard, not just the Display Name of Keyboard

Question

I lent my keyboard and trackpad to a friend, and when they were returned, they were named with his name.
I easily changed the Display Name to my own, but the Name in the Bluetooth Preferences panel remains the name of my friend.
I even found the string where his name is embedded - it is within a file called "com.apple.Bluetooth.plist" inside Library > Preferences.
I downloaded the Developer app called XCode, which allowed me to edit a copy of "com.apple.Bluetooth.plist", and put my own name where it incorrectly says my friend's name. I then dragged the copy into the Library > Preferences after trashing the incorrect one.
Proble solved, right?
But on restart - or even after sleep - my iMac alters the corrected file and returns it to the incorrect name - the name of my friend.
Seemingly, it must be using some info in a cache somewhere. So I read that Bluetooth caches may be stored in the PRAM of an iMac, so I tried the technique of restarting while emptying the PRAM by holding Ctrl-Option-P-R, but that did not help. Honestly I am not sure that the PRAM empties when one is using a wireless keyboard anyway, since the Mac is probably starting for awhile before it gets around to checking on its Bluetooth devices. But, in any case it did not work to get rid of my friend's name.
I am *this* close to buying a brand new keyboard and trackpad so I can be rid of the accursed name.
There must be SOME way for my iMac to treat my existing keyboard and trackpad as if they were brand new, and get rid of the damned old incorrect info!
Anyone found a solution to this? I've seen other threads where people failed.

Answer 1

Holy snit, I found the solution.
For the keyboard:
In the Bluetooth Preferences, when you highlight the Keyboard and click the gear, click Rename, and - this is the part that everyone I've read about has failed to do - change the Display Name from, say, Will's Keyboard to Will B's keyboard. That changes the Display Name, which we already knew and which wasn't the point. The point is that it also changes the Name. Then, again change the name back to Will's Keyboard, and both the Display Name and the Name changes to Will's Keyboard.
For the Trackpad:
It doesn't work exactly the same, so be careful! Read the following in its entirety first before following any of the steps or you will be unpleasantly surprised!
In the Bluetooth Preferences, highlight the Trackpad and click the gear, click Rename, and - this is the part that everyone I've read about has failed to do - change the Display Name from, say, Will's Trackpad to Will B's Trackpad (pick the latter name VERY CAREFULLY BECAUSE IT WONT GO AWAY!). That changes the Display Name and it also changes the Name, and you will think everything is going fine. It isn't. Then, again change the name back to Will's Trackpad, and you will find that the Display Name changes to Will's Trackpad BUT THE NAME REMAINS Will B's Trackpad. I SAY AGAIN, THE "NAME" WILL NOT UPDATE CORRECTLY, SO PICK A NAME YOU CAN LIVE WITH!