
You're going to have to pretend they are 8 weeks old and start the housetraining from the beginning.
Take them outside, where you want them to 'perform', first thing in the morning, after each meal, every time they've had a sleep, after they've been playing, and at least once an hour throughout the day. Give them a special word of command ("go pee" or something) and wait till they do it. Then loads of praise and a play.
You'll probably have to try to do this separately - it'll be very difficult to train both at the same time.
If you have to leave them unattended, put them in a pen somewhere that it doesn't matter if they soil (the utility room for instance) and make sure you clean the floor with non-ammonia products.
Good luck.
:)