Cannot remove invalid signature from expired certificate

[defaulty2rwkec350sm]

Please someone tell me there is a way out of this nightmare!!!

I want to reuse a long and complicated form I last used and signed 2 years ago.

I am the only signer. I just need to change a couple of dates to reuse the form.

The form is subsequently signed by a second person.

However, my certificate has since expired.

I get the error message that the form has an invalid signature.

I have tried trusting the expired certificate, but even after that there seems to be no way of removing my now invalid signature.

If I try to Validate All Signatures I get:

Here are the relevant screen shots.

[defaulty2rwkec350sm]

UPDATE and NOTE: If I choose to view signed version, the signature becomes valid, but I still cannot remove it from a copy of that version.

[MikelKlink]

Do you still have the private key associated with that certificate registered with your Acrobat instance? 

Acrobat normally does allow the original creator of a signature to remove their signature, but to recognize you as that creator, it most likely needs to see that key.