If you label yourself as a non-resident, the form will automatically populate and generate the non-resident return.
however, there is a glitch if you have any employment income in a province. I had fees from serving on a board of directors of a Canadian company. In that case you have to change your province of residence to the province that you earned the employment income in in order to properly calculate the Ontario taxes and to eliminate the federal surtax which applies to income NOT earned in a province.
you can leave your address as the foreign address.
