Many clock hands are just a friction fit onto a tube or a shaft. A VERY VERY gentle squeeze on the hand tube with a small pair of pliers will tend to make the hole slightly eccentric and a better push fit. Watchmakers have pliers with a screw stop which can be adjusted to a snug fit on the tube and then another quarter of a turn on the screw allows them to close slightly more. An alternative method is to GENTLY tap the open end of the hand tube whilst supporting the hand on a solid base to spread the metal and grip the inner tube or shaft. Very fine work which I have done in the past when my hands were steadier and eyes sharper!
https://www.esslinger.com/bergeon-47...cannon-pinion/
The cannon pinion tighteners are similar to the adjustable plier tool.