Wireless Printer Install Help

This is my current set up:

I have a desktop computer upstairs with a router and an HP printer.

I have a laptop that I use downstairs and if I want to print, I must turn on the desktop upstairs and then I can print from my laptop from anywhere in the house.

I purchased a wireless Canon printer the MP495 and want to set it up downstairs to use with my laptop.

I think I know how to set up the wireless Canon, but how do I get my laptop to use that printer as the default instead of the HP that is upstairs?

Any help appreciated. I plan to do the setup with the new wireless Canon later today or tomorrow and believe all I have to do is have the laptop on and online with my router and then install the software that came with the new Canon and follow the instructions that include a final connect of my laptop to the Canon and then I should be good to go, but just not sure how to use it as the default. I don't want to disconnect the HP that I have upstairs with the desktop.

Thanks,
Candee