There is no form "to remove the sponsorship" also there are no legal ways you x-spouse may force you to pay his bills and etc. using Affidafit of Support you signed, you can always say "my financinal situation has been changed and etc..."
If you get divorced BEFORE your spouse gets a green card it's his problem to convince the Immigration that the marriage was not fake.
Alex.

Thanx! But all marirage was a fake to beginning with!!!! Fraud!!!

There is anyone how had experience with sponsorship and marriage fraud, share with forum.

If he tells the immigration that the marriage was a fake then he will be deported right away.
You may also get in troubles, since the fake marriage is a crime,however for you this may end up to be a fine up to 10k or something.
Conclusion: do not do fake marriages !
Alex.

Alex,no,no, no a marriage was real from my side!!!!!!!!! A person take advantage on K-1 to come to USA.

Then I do not think you would have problems. It's his problem to convince the Immigration to finish his immigration process, after the divorce you do not have to show up at the interview.
As for the sponsorship I've expalined this is not "legally enforcable", so he can not really go to the court and force you supporting him. So forget about this paper.
Alex.