Barcelona Qualifying tickets

[Lawsome]

Currently in Barcelona and want to get tickets for tomorrow's qualifying.

Anyone know the best way to do this or even if it's possible to rock up and pay at the gate?

EDIT: bought them online. What's the best way to get there, from the gothic quarter from which we are staying?
Thanks

P.S any other advice would be greatly appreciated

Edited by Lawsome on Friday 10th May 18:48