Copy these files into the darknet repository directly, you can use something like:
./darknet detector train cfg/obj.data cfg/yolo-obj.cfg darknet19_448conv.23
Make sure you build darknet with GPU=1 and CUDADNN otherwise it will be really slow.
Pretrained models at http://coconot-models.ap-southeast-2.s3.amazonaws.com/coconot-models.tar.bz2
They might be overfitted. ¯_(ツ)_/¯