You need a tank atleast 75 gallons (125 is much better) with sand and pvc pipe caves. You'll want one male and 3-4 females, the male will need to be older than the females as the males take longer to mature. I think males have to be older than 3 years to spawn, provided his growth wasn't stunted and he's been taken care of well. Females can spawn at around 2 years of age, but the older and bigger they are the more fry they'll produce. You'll also need an egg tumbler to hatch the fry in. Frontosa are mouth brooders so the females carry the eggs around in their mouths until they're free swimming. When you see that one of the females has a distended buccal cavity (lower jaw) that means she's holding eggs. I would let the female hold for as long as possible before stripping her of the eggs and moving them to the egg tumbler. Strip her if you see that she's thin and over stressed. Some frontosa mothers won't eat while they're brooding, others have no problem.
African cichlids aren't picky about spawning, so breeding them is quite easy. The problem with frontosa is the size of tank they need when they're fully grown. A colony needs to be kept in atleast a 125, but a 75 would work for breeding a small group. If anyone is interested in frontosa I know where to find a colony of 8 F1 Mpimbwe for sale.