Satoh beaver S373 front loader hydraulic pump replacement help!!!!

[rodeohand28]

1979 satoh beaver s-373 with front loader. Front loader hydraulic pump broke and now needs replaced. How do you remove this pump first and what pump would work for a replacement? I have searched both everywhere and either don’t understand what I’m needing and I am missing something on removing the pump? I removed the bolts attaching it to the frame but cannot get it off the output shaft to remove it? What am I doing wrong? Thank you