Hello Sir,
One of the methods which worked for me was, at bed time I would sleep on the floor with a sleeping bag with the pup on top and every time they moved off, I would place them outside and it was hard work, it payed off in the end as they learned very quickly.
During the day I would monitor them or place news papers down near their basket by our back door.
Then moving the papers closer to the back door, eventually taking the papers away.
The only thing I found with the latter was, a few of the pups became very very protective around me as they started to bark and growl and