You have to wait until it opens in October.
You are no longer able to find the magical quill, as the challenge has ended. You had to answer the question correctly in order to find the quill.
You had to take part in the Magical Quill challenge. It ended on the 6th of August 2011. Pottermore officially opened to all on 14th April 2012.
You had to take part in the Magic Quill challenge which involved answering a question, multiplying the answer by a certain amount and adding the answer onto a URL where you would find the Magic Quill. However, this was only for registration. Beta testers were slowly allowed to enter the site in small groups, starting in August. The challenge ended on 6th August 2011.
At 8am GMT on the 31st July the 'Magic Quill' challenge started on the Pottermore website. For seven days one question is posted and to have a chance at being a Beta Tester you had to answer the question, multiply it the answer by a provided number and add it on to the end of another URL.On the first day, the question was about the first book Harry Potter and the Philosopher's Stone on the second day it was about the second book Harry Potter and the Chamber of Secrets and so on until the seventh. Each day the question was easier than the day before.One million people were able to respond to this an become Beta Testers. They have now been picked and the challenge ended on the 6th August 2011.
Quill Award ended in 2008.
Infinite Challenge ended in 2012.
Warrior Challenge ended in 2003.
Sports Challenge ended in 1979-09.
The Magic Tree ended in 2006.
The Magic Roundabout ended in 1971.
Magic Bird ended in 2007.
Magic Journeys ended in 1993.