Sentence:  "Yorke" hereupon conſults with his ſpeciall friends; ... how "Yorke might get the Crowne of England", and for that cauſe "how to ruine or <WSD>fret</WSD> out the Duke of Sommerſet"; who ſtanding, they were to looke for ſtrong oppoſition. 
Meaning of the word marked with <WSD> tags:  "In the form" '''fret out''': to squander, to waste.