Heki blind assembly - replacement

ValDa

Has anyone replaced the blind and flyscreen assembly on their Heki rooflight?  Ours has become very badly marked, and the edges have stretch, meaning it no longer works properly sometimes.   I've replaced a 'normal' rooflight with a Mini Heki in the past,
so have no problems in doing the work, just wondered how difficult a job it is?

Also, does anyone know of the best place to buy a replacement (or does anyone have one taking up space in their garage/workshop/fixed bed space..........................?)