Lets back up a bit. The needles don’t fit into the liners, they fit on them. The liners snap onto the rod and cap first giving the needles a hard bearing surface to run on along with the crank journal.
Get your rod and cap properly aligned by finding the small pip or cast in marks on them. Then snap the liners onto the rod and cap so the pip marks remain aligned when being assembled. Try putting the cap onto the rod to make sure everything is fitted properly before trying to do it in the motor. If everything fits and lines up correctly, you are good to go.
This photo shows the order in which they go.