A lot of missing information is required for someone to be of assistance. Bed temperature, nozzle temperature, printing material, any adhesive used.
One method that has worked for me in the past for these difficult jobs is to bring the bed up to temperature manually and apply with an eye dropper or similar a 50-50 mix of denatured alcohol and water. Let the bed cool. It may be necessary to apply a substantial amount, to encircle the print, ensuring that it gets under the edges. As the bed cools, the substance will evaporate. Heat the bed and apply as many times as needed to pry the part loose. Check if you can pop it free after each application, don't wait for it to evaporate. I've posted this answer in another forum and the response from the OP was that it worked well.