Speedometer Cable Replacement HELP......
 

I've got an '82 automatic 6.2 diesel that I purchased less than a yr ago. The truck needs the obvious TLC and such but the main issue I want to fix first is the speedometer cable due to it not working and get the cluster in working order. I looked and saw that I could replace the top short cable and was wondering if it was a PITA or something simple I could do in about an hour or so? I already took the dash out and such. Is there a 'how to' here that I couldn't find? Thanks in advance!!!