Yes, you can do it online. Here's how:
1. Go to koodomobile.com
2. Click on Phones
3. Choose the phone you would like to order and click Add to Cart
4. Click on Checkout which is under the box that reads “Build your Package”
5. Click once again on Check out now
6. Click on Existing Customer
7. Log into your Self-Serve account and you will be able to use the Tab points you have available.