How to replace " (double quotes) with '

I am trying to read a text file and wish to replace all occurences of double quotes with a single quote.

I have tried :
Replace(textstring , " \" " , " ' ")
Replace(textstring , ' " ' , " ' ")

But get an error.

Code:

---

'use the characters code
myStr = Replace(myStr, Chr(34), "'")

'or this works.
myStr = Replace(myStr, """", "'")

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