koala

Hi, welcome to TSF

This might sound dangerous, but it's a trick used all the time by techs. Remove the hard drive and put it in an air-tight plastic bag with as much air removed as possible. Put this in the freezer for a few hours, then reconnect it and quickly copy as much data as possible to the external drive. You might only get an hour's use out of it before it starts clicking again, but the process can be repeated until the drive finally dies.