Divorce. A sad tale unto itself, but for those petitioners that were granted conditional residency based on their marriage to a US citizen, it can become an even greater nightmare.
A common situation I see is that a petitioner divorces within the two years of becoming a conditional resident. They can no longer rely on their spouse to file the I-751 for them, so can they file it themself?
The answer is yes. The real devil is in the details. The USCIS will raise red flags and will place the self-petitioner under increased scrutiny believing the marriage was not bona fide. How do you handle this matter?
Your best bet is not to try to prepare the petition on your own. An expereinced immigration attorney can help you provide the proper documentation to the USCIS to at least have them schedule you for an interview and not outright deny your petition or send you a laundry list of items in a Request For Evidence that you could not properly answer.
If you do not take the time to properly prepare and present your I-751 petition packet to the USCIS, you may find yourself in Immigration Court having to defend yourself in removal proceedings back to your home country.