How can I clean the holes at the top of the collection bucket as I find they are getting clogged up with the dust please help.

They need maintenance every few months. You have to clean very fine dust out of the central cylinder. Remove the dust collector and take the core cylinder out of the glass casing. Use another vacuum to remove debris out of the little holes on the cylinder. Check for caked dust at the top of the cylinder. Pat the cylinder gently to dislodge it into the trash. Finally, remove and wash the permanent filter. Let it dry thoroughly before reinstalling and using the machine again.