93 2500 front sway bar

I have a bad upper ball joint on my truck and when i was checking it, i noticed that my sway bar link where it connects the sway bar to the control arm is GONE. Are they easy to change? Should i plan for a long night? Do i have to go to GM to get one or will an auto parts store carry them? Any idea why it would just fall off? Thanks

You can get the complete link kits at you local auto part store. They are easy to change.

thank you