Using CSV data to rename images

So I seem to get the gist of how to rename the folders, but it would not use the CSV data, please correct me if I am wrong.

1) I load all the files I want to rename.
2) I then import CSV data, which has two columns (first one is old and second is the new name)
3) I then import the names but nothing changes.

I tried another method,

1) I try the files from CSV method, and I have the filename with the CSV
2) I choose the base folder containing images I want to rename.
3) Everything looks fine, everything is separated correctly, but the status says Cannot find source.

I am so close but for some reason it says Cannot find source. I am a bit of a newbie at this so please help, thanks.

The text box looks like this:
http://prntscr.com/w9byo8

Reply to #1:
You need to specify the full filename in column 1 of the csv file - ie complete with extension.