roof question

hi i just got jameses roof scoop extension bit think the middle bit that comes on the 220 bit to high, is it easy to take off so i can firbeglass and smooth bit between extension and orginal piece. is it glued or screwed under the head lining?

thanks for any help thought id ask you guys before tackling it

Glued to the outer roof lining and if Lotus have used as much glue on yours as they did on mine very hard to get off without doing damage