I have an amended K-1 and need to amend my return which has already been filed. How do I amend my taxes now that I have an amended K-1.

You can amend your tax return using the instructions in the FAQ below. However, you should not try to amend your return until it has been fully processed and you have received your refund or your payment has cleared.  Amended returns do not “catch up” to your original return and replace them; they are processed as two separate returns.  

Amended returns have to be printed and filed by mail.  It can take the IRS up to 12 weeks or longer to process them.   If you are due a larger refund than on your original return, your amended return should only show the difference and you will receive a separate check for it.  If you owe money on your amended return, it will show only the new amount owed, you will have to mail a check with the return.

You can check the status of your Form 1040X, Amended U.S. Individual Income Tax Return, using the Where's My Amended Return? online tool or by calling the toll-free telephone number 866-464-2050 three weeks after you file your amended return.

Do I enter the amended K-1 as a new K-1 and delete the original K-1, or do I just change the numbers in the original K-1?

Once you start the amendment process you will return to the K-1 you originally  entered and correct the changed figures.  Do not create a new K-1.