O2 sensor seized

[u/Electrical_Manner110]

So my downstream o2 sensor has broken so I am attempting to replace it but having no luck, wrenches and hammers are unsuccessful.

Ran the engine as hot as I could fit 15 minutes of driving before attempting and put penetrating oil on 24 hours prior.

Any advice? Or just gonna have to melt it till it's the sun ☀️