How about doing it by natural wastage, ie, when the person leaves the job, you don't replace them
That often happens, or people are employed within the same industry, but doing a different job.
The writing is usually on the wall, but many people don't pay attention to what's going on around them, and wake up one day wondering what the fuck happened.
A simple example.
If you're employed to read utility meters, it's been pretty obvious for a long time that this job and the number of people needed is going down, due to technology.
This type of change is happening constantly, don't bury your head in the sand.