Cutting out square tapered bottom bracket?
I've been dealing with a seized square taper bottom bracket. After a lot of unsuccessful methods of removal, the 20 year old bottom bracket splines have given way on both the drive and non-drive side and they no longer grip the BB tool even with a c clamp holding the tool in.
At this point I knocked the spindle and bearings out now I'm stuck with the BB shell casing.
The frame is chromoly and the ends are tapered in so I'm thinking the best methods of removal is a hackzall through the middle then hammering the cups inwards? Looks similar to this https://www.youtube.com/shorts/D8fUl4Pmhh8
I think it's a BB-UN52 in there but can't confirm. https://si.shimano.com/en/pdfs/ev/BB-UN52-1542/EV-BB-UN52-1542A.pdf
Any suggestions appreciated before I end up tossing the bike.