If your system is set to use timesheet approval then you will submit your time rather than post it.
This means it can then get approved, queried, put on hold or rejected.
Queried and rejected are the only two actions that then require further input from you and they will appear at the bottom of your timesheets:
If you have a queried timesheet the approver has to give a reason to query them, so you can open it up and see the 'Approver's notes':
At this point you can amend any part of the original timesheet from charge code onwards - ie it has to remain for the same job / phase / stage (if applicable). Equally if there are no amends and you wish to resubmit as stands this is also fine.
The mandatory requirement is to fill in the 'Submitter's notes' field, perhaps to either state why they have not changed or what you have amended.
Once they are re-submitted they will go back through the standard process as before.
Equally you can simply delete the timesheet if it is no longer valid.