After having passed all exams:
You will need to submit a completed EASA Form 19 together with the required documentation to your competent authority - UK CAA.
You apply for the licence with your work experience log book signed by one of your supervisors with sufficient work experience!Start filling out as soon as possible!
Here is a free EASA work experience log book from the SWISS authorities!
Work experience documentation for the EASA part 66 Logbook Canada