I have a Raspi 2b+ (one of many Raspis I own). I installed Rasbian on it via Noobs around 1 year ago and made many modifications to the install (mainly hacking my own PIR powered ambilight / picture slide show). Annoyingly I did all this on an 8GB card that has now run out of space due to the photos I store on it (for the picture slide show)
I have a larger card and I assumed I could image the 8GB card (using win32diskimager) and write that to a larger 64GB card and then simply run raspi-config and select the Expand File system option). BUT, when I do this, I get a message saying it looks like I used Noobs and the filesystem is already expanded, which it isn't as df -h still lists the 64GB card as 8GB

I have found this info: http://elinux.org/RPi_Resize_Flash_Partitions but these instructions (the manual instructions) seem to be written for non Noobs installs and I was concerned if I went ahead, I might bork my install entirely since it is Noobs based.
Any one any ideas how to get round this?