It's easy to learn. First, insert the sewing needle with the thread hole facing down: as shown in the figure. Then, hold one side and let the crochet hook come out through the needle hole (be careful with your hands)
When we are traveling or on business trips, and need to mend something, we always think of our mothers! How she used to squint her eyes and frown as she stitched this thread through?
Needle Thru Guide Detailed Instruction Manual

International Senior Recommended Product - Quick Wire Puller
Function: Used for quickly threading hand sewing needles and sewing machine needles.
Hand stitching needle: 1. First, insert the needle into the thread guide hole, with the needle hole facing down.
2. Gently press the press plate to allow the hook to pass through the needle hole.
3. Hang the thread on the crochet hook, loosen the press plate, and pull the needle to create the desired pattern.
4. If the wire cannot be pulled, press the pressure plate in to make the wire disengage.
5. When storing the needle, press the press plate in, place the needle in, and take the needle in the same way.
Sewing Needle: 1. Insert the crochet hook into the needle hole of the sewing machine needle, and hang the thread on the crochet hook. Simply pull the thread guide open. (Suitable for 9-16 needles.)
2. Tie the line to the blade.
Notes: The thread should not be too thick or too many, and do not apply too much force to avoid damaging the crochet hook.