Click in the word, press Ctrl-D (on my Windows computer) and Ctrl-D again to continue to select the same word. Then overtype.
I don't know if there is another command that might select all instances on the same line
but then again, how many times would the word recur?
"I'm here to save your life. But if I'm going to do that, I'll need total uninanonynymity." Me Myself & Irene.