Yes, you can file Form I-751 to remove conditions even if you’re divorced, by requesting a waiver of the joint filing requirement.

 You do not need your ex-spouse’s cooperation to file the I-751 if the marriage was entered into in good faith but ended in divorce.

 You’ll need to show proof that the marriage was real when it began, even though it didn’t work out like shared finances, leases, photos, messages, etc.

You can file the I-751 at any time after receiving your conditional green card not just within the 90-day window if you're applying alone.