Thank you, I have to say I am no expert but followed the instructions and have ended up with both sets of images displaying in the mac hard drive, the ones that were on the external drive still have the exclamation mark in the corner and these cannot be found but they are next to a copy of the same image that is fully accessible and able to be developed. Is there any way that the catalogue used to store all the developments of the original DNG's can be used on this new set on images in this case, or is it a case of going through them all again picking and developing them again? (There are quite a few images and was just wanting to save a bit of time if possible!)
Thanks for your help so far it really is appreciated.
This is exactly what the instructions are explaining. For the photos with the exclamation point, you click on the exclamation point and locate the replacement file on the internal harddisk.
If entire folders need to be reconnected, then you can reconnect entire folder(s), right-click on the folder and select "Find Missing Folder".
You probably want to first delete the replacement files from Lightroom, but not from the hard disk.