If you have an external hard drive, you can connect this to your working
computer and have the Selkie Rescue Center copy your files to it, rather than
storing anything on your laptop.
I’m afraid you can’t run Selkie Rescue so that it backs up from the bad hard drive to
the good in a single machine. However, you can use Selkie’s rescue center on
your working computer to select groups of files or folders rather than all
your data at once. This will let you copy your files in groups and move it to
other media to make room for the rest.