You need to file a motion and have that approved if you want to waive filing fees. Look at the checklist and the guide below for some assistance http://www.courts.state.co.us/Forms/Forms_List.cfm?Form_Type_ID=176 and speak with the court clerks on the general forms.
This answer is for informational purposes only and is not legal advice regarding your question and does not establish an attorney-client relationship.
The answer to your question depends in large part on what type of fees you are unable to pay.
You can reach Harkess & Salter LLC at (303) 531-5380 or info@Harkess-Salter.com. Stephen Harkess is an attorney licensed in the state and federal courts of Colorado. This answer is for general information only and does not create an attorney client relationship between Stephen Harkess or Harkess & Salter LLC and any person. You should schedule a consultation with an attorney to discuss the specifics of your legal issues.
If they are MANDATORY criminal court costs, they can not be waived and unless family or friends help you out, there is not agency out there to help you pay them. If they are civil court costs, follow Mr. Murillo's advice and file a Motion to Waive Court Costs.
The information provided in this answer does not create an attorney-client relationship. If you are interested in his legal services, feel free to call Chris at (303) 409-7635 at his law office in the Denver Tech Center. All initial consultations are free of charge.