Only manually.
I did it in the opposite direction, closing my dotCOM listings and moving them to dotCA when dotCOM brought in the stupid shipping cap on media. (I sell books).
It took ages since I had over 1500 unique listings at the time. But I am now able to use Canada Post Calculated Shipping , which is a great time and money saver over Flat Rate shipping charges which are all I could use on dotCOM.
