Programming :: Replacing A String Of Text That Includes "/"

Suppose I have a file named temp.txt

cat temp.txt
word/one/two/three

If I would like to replace "one" with "six" I would do this:

cat temp.txt | sed 's/one/six/'
word/six/two/three

Now I want to replace "one/two" with "six/seven" and these options don't work:
cat temp.txt | sed 's/one/two/six/seven/' (OFCOURSE)
cat temp.txt | sed 's/"one/two"/"six/seven"/'

I even want to be able to replace "one/two" with "six/seven/eight"