bash help please for noob

Hello all
I have been trying to convert to .txt documents for keeping track of my life. I stubbled on todo.txt which seems to offer lots of ways to interact with .txt documents via terminal. HOwever, I am having the hardest time chaing basic things in my .bash_profile...First off, it is in my home directory i.e

/Users/narayanankasthuri/.bash_profile.rtf

and I open it and edit it in text editor...is that the right program to use...should it be saved as a .rtf file? I am literally trying to do the following found on an site for intro terminal:
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Open up either your .bashrc file. The way we set what information is displayed in the prompt is with the PS1 variable. Add this to the file:
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PS1='->'
Notice that I don’t put spaces on either side of the equals sign; that’s necessary. Save this file in your home directory and re-open a terminal window. Now, you should have a prompt that looks like this:
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no matter what I change in the .bash_profile in text editor I can not make this happen....I know i am an idiot but please enlighten me!

thanks