Hope This Helps, Its For The 75-79 GL1000....
Ok This Is The Adjustment Prosidure, But It Can Give You The Tips To Changing Out The Cable

Step One:RED Loosen Up The Upper Adjuster And Nut All The Way
Step Three:BLUE Remove The Cable From The Clutch Lever, You Might Have To Remove The Lever From The Handle Bars To Make This Easyer On A Stiff Cable

Step Four:RED Loosen The Lower Adjuster All The Way

Step Five: Remove The Clutch Arm Cover On The Back Of The Motor
Step Six:BLUE Remove The Clutch Cable From The The Clutch Arm

Snake The Old Cable Out Of The Bike And Install The New One In Reverse Steps And Make All Of Your Adjustments...
p.s. The Steps Are Out Of Order But They Go With The Picts
Hope This Helps, By The Way Comes From The Honda Shop Manual...