[Motorola] On-Hook Microphone Mod

[Deane Bouvier]

I have made the on-hook jumper mod to two types of black microphones used
with GM300 and M1225 radios (e.g. HMN3596A) to enable Rx PL without a mic
clip.    
 
I now have a white mic with a M1225 (HMN1056C) and want to do the same.
The black mics had three screws on the back which made it easy to open and
make the mod.  The white mic has no screws and it is unclear how to open
it.  Does anyone how to open it in order to put the jumper in? I don't want
to start randomly prying and mess it up.
 
Thanks,

Deane Bouvier, 
N5DQ