Ceiling Light Shade Removal Question

[agricola]

1 Try turning the black base, it may be screwed onto a holder
2 Look for timing marks on both the black and white sections, if there are, line them up and pull the two apart
3 Wrap the thing in cling film and tap the white glass with a hammer, the film should stop the glass splintering all ove rthe floor and into your eyes, then carefully remove the offending object