I took this pic for a friend, its a 3 to 9 Nikko. But most scopes can be readjusted.
You may need to heat it up a bit with a Hair Dryer, (not a gas torch) to break any sealer used.

You need to loosen the front lock ring and the front lens carrier.
Two jar lid grips are handy for that.
Screw the lens out a bit till the focus is where you want it. Then lock it up again.