I want to un-submit my e-file my tax return to correct and redo the return.

[jerry2000]

It is not possible to do that.
Submitting the return for filing is just like dropping it into a mailbox - you can not get it back or change it.

Once you submit  and find that you need to make a change, you will have to wait until the IRS either accepts or rejects the return. If the return is rejected by the IRS, then you can make the necessary changes and resubmit it. If the return is accepted, then the only way to change it is to prepare an amended return and file it by mail.

[arcangel_81]

My e file status is still 'pending'...can I cancel the submission?

[jerry2000]

No. Once submitted, it is not possible to cancel the submission. You must wait until you get an accept or reject from the IRS and that will occur 24 to 48 hours after the IRS begins to process returns on Jan 23. Before then, do absolutely nothing to your return. If the IRS rejects your return, then make the necessary corrections and resubmit. It the IRS accepts your return then you will have to prepare an amended return and file it by mail.