* place a metal pan with shavings in every corner they pee (i bought the cheap ones dogs eat from - biggest model)
* fill the pans with what they like most, aubiose, shavings,...
* if you have put down several pans, remove one every x days, normally they will go to the remaining pans. Repeat till you have 1 left
* if I don't clean their shavings every 2 days and leave it in for 3 for example, they refuse to "go" in the dirty pans (who can blame them?) clean frequently!
* don't clean the pans too thouroughly neither; from what I have been told it's important to keep some of their scent in there to encourage the use fo the potty