Philips HC5450 Disassembly

First step is to take off the front like you normally do when cleaning.

Pry off the silver bezel. This is attached pretty firmly. Start at the front, and go all the way. The front has tabs with a large hook, so it might only fully disassemble when you have pried it loose a long way and you are able to flex the bezel a little.

During this step, I broke the last tab of the silver bezel. Too bad, but the bezel is still firmly attached when reassembling.

Use a T8 Torx driver to remove the four screws.

Undo the top part of the black body. I started at the back. It is retained with clips, but is not as firmly attached as the silver bezel.

The PCB can now be taken out. The connection to the charging pins is not screwed or soldered, but a U-shaped connector that's just retained by friction.

The assembly is held in place by one Torx T8 screw, identical to those from step 3.

The ring of the length-adjustment-assembly can slide down. A little pin-and-spring will fall out - don't loose it! It is used to make the "clicking" feedback when rotating the ring.

I did not disassemble this assembly any further.