retool vs revamp

retool

verb
  • To adjust; to optimize; to rebuild. 

revamp

verb
  • To improve, renew, renovate, or revise (something). 

noun
  • An act of improving, renewing, renovating, or revising something; an improvement, renovation, revamping, or revision. 

How often have the words retool and revamp occurred in a corpus of books? (source: Google Ngram Viewer )