I tore out ninety inches worth of old degraded caulk and inserted new caulk in it's place.
I hacked the old caulk loose with a hammer and axe head and then ripped it off in one large jerk. Then I hacked away the leftover shreds of old caulk with a boxcutter.
When my new caulk proved too thick to fit in the crack I sliced some of its length away with a young trowel.
In the end it took me about an hour and a half to change caulks. It's a simple job but hotter and heavier than you'd think.