Buy out inherited property

[Mark Chambers]

My wife and her sister inherited their dad’s house after he passed. The house is in Northern California and we live in Pennsylvania. We want to buy her sister out of the property, but don’t know where to begin because we’ve only bought 3 properties in Pennsylvania through a realtor. 
Where do we begin?  Would it be a conventional mortgage as a 2nd home?  Will financing be easier since she’s technically already an owner?  How to we coordinate to get the title transfer?  

A lot of this would have been handled a lot better during probate but the attorney was pretty useless and we definitely don’t want to use her for trying to figure this out. 

The house was appraised at 450k and we’d be paying her sister 200k. Any help or guidance is appreciated!