step parents

Hi, I am looking for ideas on how to include my step father and step mother in the ceremony. They are paying a BIG portion of the wedding with my mom and dad. The only thing I could think of is having them do a reading, but I think because of stage fright, that would not happen. Does anyone have any other ideas on how to include them? There is no mass also, so we can;t have them bring the offerings.

Thanks for all the help!!!!