how do I remove & replace rear lens cover on 09 estate?

My MOT's due and I've just cracked the offside rear lens cover. How do i get this out and replace? All sensible rememdies gratefully accepted before 15th July. This is St Swithins day when , if it rains, it will continue to do so fro 40 days and nights.id my car fails the MOT for this damage I may well weep for 40 days and nights.