66' Power Streering box swap? How hard a job?
 

My truck already has the power steering conversion. Truck came with it and I have no clue whose kit is used. The steering box leaks so I want to replace it. I've tried to find threads on just swapping the old for new, but all the threads I found are for new conversion. How hard is this to attempt? What other parts are involved that should be replaced at the same time. I'm not looking for a front end rebuild at this time as finances won't allow that. Is it just a new box and pitman arm, new fluid, and bolt it back together? Any and all tips appreciated. Thanks in advance.
Jon