When you have collected enough Fido points, you can redeem your Fido dollars for a new phone. How you do that is by calling up the Fido Customer service and telling them which phone you want to get. These days you would usually need to get into a two years contract to redeem your Fido dollars and get a new phone. You can also purchase some phones without contract and redeem your Fido dollars at the same time.
If you don't want to get a new phone with your Fido dollars, you can redeem Fido dollars for free text messages or extra talk time monthly or extra calling features such as call waiting, call transfer, voicemail.