Once the fly rod is assembled, and the reel is attached, you need to run the fly line through the guides on the fly rod....

Step 1. Take off your fishing hat, and place it on the ground, with the inside of the hat facing up to the sky.

Step 2. Place the the Reel Seat Cap inside the cap.

Step 3. Strip off enough line from the reel, so you have more line than the length of your fly rod.

Step 4. Fold over the tip end of your fly line so you have a double segment of fly line to run throught the guides.

Step 5. With one hand cradled under the fly rod (below the guide), insert the doubled fly line through each of the guides.

Step 6. Move forward with the hand cradling the fly rod as you move to the next guide.

Repeat Step 5 & 6. until the looped fly line emerges through the tip-top guide.

Only then you pull the remaining fly line and the tapered leader, carefully through all the guides. If there is an obstruction preventing the rest of the line and leader from passing through the guides. Stop and go back to see what is restricting the line.

The hat keeps the line and the reel free of any dirt or contamination.

That how you "Walk the Line!"

~Parnelli.