Fixing T3 slips with errors which were filed on March 31st

I prepared a T3 and intended to allocate the income to 3 beneficiaries, but by mistake, I filed the slips all the income was allocated to a 4th beneficiary.  So I want to cancel the slip to the 4th beneficiary and file the slips for the 3 correct beneficiaries. 

What I did in Profile was

Enter the correct amounts on the T3 slips for the 3 correct beneficiaries

Designated these slips “O” for original

Deleted all the $ entries on slip to 4th beneficiary

Designated this slip “C” for cancelled

When I go to file it asks me whether I’m filing Original, Amended and Cancelled.

My questions are - 

Did I prepare/correct the slips properly?

When I cancel the one slip is it okay that I zero out the original amounts entered or do I leave it in

Do I file twice, once under Original and once under Cancelled

If so, when I file Original is it okay that I leave the Cancelled slip in the file ie. don’t want to delete it of course…does the system only recognize the Cancelled slips

Same question for Cancelled…can I leave the Original slips in