Dismantling a Seized Pin-Bearing Bush

Dismantling an articulation Pin-Bearing Bush which is seized. The pin is 60 mm diameter, looks like never was greased. I am using de greaser and a hydraulic jack of 100 T and not movement is recorded.

I remember I read somewhere about a method of using the electrical current to burn the rust between the surfaces in contact.

Did someone has any suggestions

Thanks.