1.Please check whether the size of the door frame match with the door leaf , or its need to be cut. 2.Use screws assemble the frame, the architrave are not to be installed. 3.Fasten the door frame to the hole with fixed iron plate. 4.Install hinges to secure the door leaf to the door frame. 5.Install the lock and stopper. 6.Install architraves to the door frame. Hihaus is a professional and experienced suppliers for aluminium windows and doors , wooden doors ,if need more help, please contact us.