Order owner:
You can login to your ticket dashboard at: https://qatar.websummit.com/my/wsq25/login using the email address you made your order with. A login link will be sent to this email. 

Inside your ticket dashboard you can assign/reassign your ticket(s) by clicking "manage items".

Ticket holder:
If you aren't the order owner but know you have a ticket assigned to you, you can also log in at 
https://qatar.websummit.com/my/wsq25/login to view your ticket. 

You will not be able to reassign your ticket. Only the order owner can make these changes.