1. In case you can not print on the full paper (e.g. with laser printers) you need to cut off the edges to get the right aspect ratio.
2. Cut along the outer line (if you have printed out with the option showing folding lines).
3. If you can print edgeless than you can start with the step nr. 4. You should now have your printed sheet in the right aspect ratio.
4. Search for the Black Line with the Number 1 beside and fold it along. It is just in the middle of the paper.
5. Open the folded sheet again, turn it 90 degree, search for Number 2 and fold the right upper corner to the middleline.
6. Search for Number 3 and fold the left upper corner to the middleline.
7. Search for Number 4 on the left side and fold the new upper left corner around this line to the middel. Search for Number 5 on the right side and fold the new upper right corner around this line to the middel.
8. Fold the sheet again on the middle line from step 4 and turn it 90 degree.
9. Search for Number 6 and fold down the wing along this line.
10. Search for Number 8 on the lower part of the wing and fold it up to get the stabilizer.
11. Turn around the paperplane, search for Number 7 and fold down the second wing along this line.
12. Search for Number 10 on the lower part of the wing and fold it up to get the second stabilizer.
13. You should be ready to go. Adjust the stabilizers and let if fly.