How to white out text so I can type over it?

I have a letter template I can't edit. So I want to white out some of the existing stuff in it (such as "[Address]", "[Name]", etc.) then type what needs to go into my letter. I searched for how to do this and the closest I got was the Redact function. But redacting left me with blocks of blacked out text.  Can I redact text in white instead of black, then type over the whited out secctions? 

If not, is there some other way to be able to modify the template or do I have to create a new letter from scratch?

Thanks