You will have to remove the needles again, and with the gauges in their operating position very carefully refit and press on gently.
I have done very much the same on pressure gauges, its very fiddly work.
What Brock said. I've had to do it hundreds of times on Pressure gauges when I was calibrating them.
Be gentle, and gently push them on part way, let go, check it is still lined up, press a bit more, let go again, etc until it is all the way on.
That way, if it has moved, you don;t have to pull hard to get it off again.
Best of luck.