You need to get another English of Aviation Certificate which means you need to be tested by a UK CAA approved Examiner.(list in their website).
When you have that they will mail you your EASA licence with your rating as "previously held rating"
In order to use the rating privilege,you will need to go through a UK TRTO that will decide,if your IR lapsed,on how many hours you need of ground school/simulator before your IR check.
If you are current on the same type,then they should give you only a max of 3-4 hours.(1-2 hours training followed by the check).
A TRTO training completion certificate will be issued and you will then need to mail it to the UK CAA along with the usual fees.