Bath pop-up waste removal tool

[cbk]

Hi Guys,
I'm replacing the pop-up waste on an 8yr old ideal standard bath as the old mechanism has jammed and got broken in the attempts to fix it. I can figure out how to fit the new one if I can just get the old bits out. The problem is the locking nut that holds the drain plug assembly in position. It is round with a slot in the top - like a big screw head and it is locked solid. Bath is about 8 yrs old and had good use. I've tried WD40 - tapping with hammer to loosen it etc. Biggest screwdriver I can find will not fit right across the head of the nut so it difficult to get enough grip to loosen it. Is there any kind of special removal tool that might shift it?

 

[Burnerman]

We've all got that elderly wood chisel thats been used to open tins and stir paint, haven't we.....(some of us have nowt else )
Try that, but the same effect happens when we twist the waste underside - but of course that shifts the overflow pipe too.
John

 

[HERTS P&D]

20p coin held in a pair of pliers.

Andy