Dino Attack - Try to change battery of T-rex Head (trex01)

[dirkberlin]

Hi! I bought a few Years this atomic (?) Trex (?) Bricklink, and of course the battery was extremly weak. So I tried to get the Info how it works - and found few questions, with conclusion: You can't change the battery without destruction.

A few years later, I found a cheap (2 €) dead head on local marketplace. So I've got the question: Okay, when it don't work without destruction, can it go with it? I know, it's cruel to modify Lego with tools, but... science?

Today I started.First problem: You can't open the jar very wide, but you see 2 plastic bars in it:

So I removed the jar by cutting the lower bar with a knive at the ends.

With the only the upper head, I started to search more Bars to cut them with a drill. Without any clue some kind of difficulty, but finaly
cut the 2 bars in the front. The Horns are on a soft plastic part in the middle, so had to drill by the sides of it. On the end, was a small cutout, so I used a telephone pliers, to open
the rest. Finally there are 4 glued plastic bars/pins. maybe upside the technic connection there is one more, but it opened regulary

Finally you found some parts: Left skull, right skull, jaw: Inside the tounge, horns and the light modul.

the light modul is very, very simple:

the battery is in some tray clipped into the light diffusors/eyes, when removing it, you see how cheap the trick is:

There is no real mechanism. when pulling the trigger the stamp goes direcly on the diodes pin, and push it on the + part of the battery cell, there is some foam to pull it back.
on this head the foam is missformed, and the pin is bend. Maybe the last user pushed harder and harder, to squize out light. the contacted is corred to. The battery is Tian Qiu CR927 with 3V now with 1 V.
got again some light after clean the pin.

So this is my little trip inside the brain of an nuclear Lego Monster. Was this the right way inside? no. when it is a second tour, i will starting cutting the jar inside it, not outside, now its very unmounted. with knowledge where the points are,
I would prefer smaller holes, and maybe try with pliers ealier. All pins are inside the head, with good chance to break inside.

Now I have to choose, if it's worth to repair may real Dinosaur, no spear head. Of course I can try to fix this. But it's for me a uncommon battery. Maybe there is some way to change it, and make some holder in the front on the upper head. 
There are some big holes now. 

What did you think about this trow-away Design by Lego?