Refresh env variables after editing bashrc file

Within the same window, you can simply type bash to start a new one. This is equivalent to closing the window and re-opening a new one.

Alternatively, you can type source ~/.bashrc to source the .bashrc file.

Just use

source ~/.bashrc

or

. ~/.bashrc

In addition to what others have suggested, I have found out that source won't unset the previously assigned environment variables. So, if you want to unset environment variables, you have to do it manually using unset <var>.