Condition the fish well on good quality flake and plenty of live/frozen foods. I used earthworms finely chopped too.
When the females are looking very fat, place the fish, preferably 2 males to each female in a breeding tank with some kind of coarse substrate or matting on the bottom. Some breeders use a layer of glass marbles, I used a geotextyle material made from woven strands of polypropylene. The eggs sink and disappear into this layer so the adults cannot eat them
Raise the temperature to 25C and wait for the action, which will normally take place just after lights on in the morning.
Good luck