1. Remove 3 torx-head screws on nearside scuttle-tray front.
2. Remove 3 nuts from strut-brace where fitted and raise about a foot.
3. Remove hose and clip for scuttle tray drain.
4. Raise scuttle tray and reach down to remove filter and holder.
5. Carefully unclip filter from filter holder.
6. Replace filter.
7. Reverse process.
Filter cost about £10 on Ebay.
Allow about ten minutes for the job.