The pull starts during 13:00CET on Friday 4 August. It will take place during UEFA domicile in Nyon and will be streamed live here on UEFA.com.
How will a pull work?

Clubs are seeded according to their fellow and are separate into groups. All a clubs within any organisation are systematic incidentally and identified by a number.
For any organisation of clubs, dual bowls will be prepared, one containing balls with slips of paper numbered for a seeded teams and a other containing balls with slips of paper for a unseeded teams.
A round will be taken from any play and placed into an dull third play in a middle, where they will be shuffled. One of a dual balls is drawn during random, afterwards non-stop to arrangement a series it contains, denoting a side personification during home in a initial leg.
The second round is drawn to finish a pairing. This procession afterwards relates throughout. The same procession is carried out with a remaining balls to finish all a pairings.
The ties are played on 17 and 24 August.
The 22 winners go into a organisation theatre pull in Monaco during 13:00CET on Friday 25 August, along with 16 involuntary entrants and a 10 teams degraded in a UEFA Champions League play-offs.
Article source: http://www.uefa.com/uefaeuropaleague/news/newsid=2486250.html?rss=2486250+All+you+need+to+know:+#UEL+play-off+draw