You'll be filing / amending I-751 to get conditions removed on your own. Your spouse won't be signing it anymore.
However, if you're on good terms, you can get a statement from your spouse describing how your relationship started, progressed and ended. In detail. He'd also say he doesn't object you getting conditions removed. You'll write a similar statement.
I'd also explain what took you so long to divorce and efforts in the past to save relationship. If you have proof of any marriage counselling sessions etc - that would help.
Good luck!