vi Search and Replace Commands

Press escape and then...

  Search STRING forward :   / STRING.
  Search STRING backward:   ? STRING.


  Repeat search:   n
  Repeat search in opposite direction:  N  (SHIFT-n)


Replace OLD with NEW:

 First occurrence on current line:      :s/OLD/NEW
 
 Globally (all) on current line:        :s/OLD/NEW/g

 Between two lines #,#:                 :#,#s/OLD/NEW/g
 
 Every occurrence in file:              :%s/OLD/NEW/g