How easy is it to remove fibre glass loft insulation?

I want to remove the old 100mm fibre glass insulation rolls from my loft and replace them with a SuperQuilt type option (i.e. 100mm thickness but the equivalent of the recommended 270mm thickness). I cannot add the new insulation on top, as I need to keep the total insulation below the height of the joists to allow me to put boarding down for storage.

Therefore, does anyone know how difficult/ dangerous/ unpleasant removing fibre glass rolls is? Any tips? Or should I not even bother?!?! Thanks