As for the modification to the module casing, what you want to do is lower the circuit board in the case so that it lies as close to the back case half as possible. There are a total of eight circuit board mounting post between the two case halfs {four at the front case half & four at the rear}. These post sandwich the circuit board between the case halfs.

You want to trim the post down in the back case half so that the circuit board sits as low as possible in that case half. This requires cutting out the little bubble section in the back case half where the transmitter pins enter the module. This can be seen in the photo I posted earlier. Once the circuit board is lowered, the mounting post in the front case half need to be extended by the same amount that you removed from the mounting post in the back half of the case in order to trap the circuit board between the case halfs.

I purchased some long nylon spacers at the local hardware store that were slightly larger in diameter than the OD diameter of the mounting post. I cut these to the required length and then drilled the ID of the spacer so that a recess was created so that the spacer would slip fit of the original mounting post in the top case half and extend enough to take up the distance that was created by cutting down the mounting post in the back half.

You will no longer be able to use the screws that originally held the case halfs together. You will need to countersink the holes in the back case half, and then find yourself some long #3 servo mounting screws. Countersink the screw holes in the case half so that when you screw the two case halfs together, the heads of the screws are left standing a little high. What this will do when you install the module back in the transmitter is let the screw heads push every so slightly on the back panel in the transmitter and take up the slack in the module locking tabs.

Also, once this is done, the bind button on the back of the module will actually be recessed inside the case. You will also have to make a small extension to extend the button so that it is exposed outside the case. Sorry I did not take step by step pictures while doing this little modification.