Easy, get a couple dozen put em into a 10-20 gal. Feed and watch them breed! Before ya know it You will have lots of them. Males have more color and are smaller. Good luck
pack the tank with java moss and keep them very well fed.
siphon or dip net out fry with as little disturbance as possible,the females can be fragile and die if spooked too bad within a week of giving birth.
Once you get a pregnant female within a week of birth, which you should be able to tell because she will get really fat and her gravid spot will get very dark, move her to her own tank. Have lots of plants in that tank for the fry to hide in.
if guppies are well fed you shouldn't have to remove them, i have a 4 foot tank set up for this purpose and they breed happily, i don't loose any as far as i know to parents eating them.