I forget just how ingenious DB can be!
The key for our car has been playing up more and more. A few years ago, it was the electronic receiver (of the key) inside the car that needed its battery changing. They charged us an absolute fortune for changing it.
DB had previously taken the key apart and cleaned the circuitry. For a while, it worked really well. Now it was playing up so much, that we were having to take the spare key with us when we went out.
The other day, he took it apart again. Circuitry still clean. Closer investigation revealed that where 3 little black mounds were sited, they were no longer high enough to touch their corresponding dimples (I know, I'm so technical aren't I) to complete the connection. He knew he couldn't easily raised the mounds up, so he looked at dropping the dimples down.
Utilizing an old and thin bit of cardboard plus a single hole puncher, he punched out 3 holes: