Incorrect work hours were logged on an issue - how do I correct my burndown chart?

[Julie Eberheim]

Incorrect work hours were logged one day on an issue (6000h instead of 6) it was saved and created a huge jump on our burndown chart.

I have corrected the work hours but our burndown chart is still showing the 6000h

How do I update the burndown chart to show the correct 6 hours for that day.

Help!