Angle grinder to cut taps off?

[Exedon]

I started in 1967 square tap hole baths and basins were still the norm for several years after.

 

[jeff the gasman]

Just use a holesaw from above and it will fall out.

 

[jeff the gasman]

TikTok - Make Your Day

Courtesy of one of the cc lads. @cider

 

[rreanor]

So in the end I took an angle grinder to it, cutting incisions across the tap base plate in various places then chiselling until the pieces fell off, then when there was no base plate left I just knocked it through the hole.