Unfortunately, you cannot.
I asked this question myself to the Weekly Chat with Board Hour not too long ago and was told that, since ebay Canada falls under eBay Global and USD is the currency against which all other global currencies are measured, our Sales Reports are only available that way. In USD. Regardless if you, like me, have never listed or sold in USD, that's what you get in the Sales Reports.
If you are looking for data, try running searches in the File Management Centre.
I do 'Paid and Shipped' monthly since the information is available for a limited amount of time only.
Also, your ebay account invoices have some information contained therein but it is flawed to some extent because some numbers include returns, some do not, some include fees paid and shipping and others do not, and some include unpaid item sales....
You get the picture.
