If you are in a situation where you made a small typo on a check-in, or you accidentally gave the wrong value for one of your KRs, editing your recently submitted check-in is very easy.
On the Performance Dashboard or Objective feed, find your recently submitted check-in and click the 'Edit' button.
An edit window will then open.
In the edit window, you can change the key result values, the status assessment, and the check-in message.
When you're done with your updates, click the 'Save changes' button. Your check-in will now be updated.
You'll notice that in the time stamp for the check-in, it will say '(edited)' and you can hover over the time stamp to find out when the check-in was edited.