I've done that, with a thin flat head but heavy duty screw driver, it had the same width as the pin itself, but was heavy duty enough that I probably put something like a quarter to a half of my body weight onto it, and I also added a little bit of longitudinal rocking motion to make it fully enter. Be very careful not to allow the screwdriver to slip, or it will deform the connector, and you may even hurt yourself. What may be even more finicky than the pins is the strain relief plastic which is supposed to click into place. But to be honest if that one won't click it's not the end of the world cause the main strain relief comes from crimping metal around the cable. And the metal crimping can be done with any generic hexagonal crimper tool.
Now all that being said, it doesn't make financial sense to do this, the connector is made out of:
- Plug: 1-520424-2
- Bottom shield: 520463-1
- Top shield: 520462-1
- Ferrule: 520435-1
And you need to buy all of these separately.
You can probably skip the ferrule, and use some more improvised piece of metal and some heat-shrink instead, for a slightly less solid result.
The last I looked the sum of these components was more than the cost of an entire cable from Unicomp.
I guess maybe it makes some sense if you want to make your own custom cable that is somehow different, and don't want cut up a Unicomp cable to do it.