Here you go:
Copy over the IOBluetoothFamily.kext from S/L/E to your desktop, show it´s content, Plugins and in there the content of Broadcom.....kext. Open the info.plist with TextEdit and navigate to the first device entry.
Fire up your SystemProfiler and navigate there to bluetooth. In the list of it´s properties you can find VendorID and DeviceID as hex values. Note this values or keep systemprofiler open.
Now you have to convert the values form hex to integer. Fire up terminal and type in the following short commands:
let x="ID in hex"
"Output as Integer ID "
Edit with your converted values the device entry of the with TextEdit opened Info.plist with your converted values, save the edits and install the IOBlue....kext back to S/L/E with your preferred Kextutility under repairing permissons.
After rebooting with flags -f -v, you should now be able to switch bluetooth on or off.
If you don´t use a bluetooth keyboard (mouse) deactivate the autosearch at bootime for them, especially keyboard, in the advanced options of bluetooth preferences.
PS: Please put your hardwarde in your signature like many others here have done it.