Removing cloakroom basin waste - no backnut present ?

[Rinnes]

Removing basin waste - no backnut present ?

I want to replace both the tap and the waste in the cloakroom basin - the tap is showing corrosion though it still works fine. Waste is OK but needs to be changed to a click-clack type because new tap will not have the incorporated button/lever which currently pops up the waste stopper.

Problem is that I can't see how to remove the existing waste. I expected there to be a backnut under the basin which could be undone to free off the waste. There doesn't appear to be any nut or any flats that a spanner could grip onto .

I've peered down the plughole from above thinking that maybe there's some screw or nut that undoes from above, but can't see anything.

Any help would be appreciated. ! Thanks.

 

[cjg]

THE plug hole part is screwed down into the base , remove bar from base ,undo the plastic waste pipe, then twist the base unit to undo, hope thts clear,

 

[Rinnes]

THE plug hole part is screwed down into the base , remove bar from base ,undo the plastic waste pipe, then twist the base unit to undo, hope thts clear,

That’s great thanks and makes a lot of sense. I’ll have a go when the new tap and waste arrive.