I thought those were the instructions my link lead to
Oh well these are the steps to follow:
A. Please find your Customer Code for the unlock system (depending on what you owned first, it will be an original 8 digit coupon code that you used to get a 25 digit unlock code or a 7 digit registration code that came with a unit and a particular software product). Please see "What is the difference between a 7 digit unlock registration code and an 8 digit original coupon code?"
After locating your Garmin Customer Code, complete the following steps:
1. Open MapSource.
2. Open the Unlock Wizard (either with CTRL + U or under "Utilities/Unlock Maps"). Click "Next".
3. Choose "No, I need to get a 25-character unlock code". Click "Next".
4. Enter your information and choose your emailing options. Click "Next".
5. Click "Next" for the UnlockWizard to connect to the Internet. Note - If you are using AOL, MSN, ATT WorldNet, or a similar Internet Service Provider, you will need to start the service before clicking "Next".
6. Enter your Garmin Customer Code (the 7 or 8 digit code). Click "Next".
7. Verify the information that appears. Click "Next".
8. Choose the option: "Unlock Additional Garmin Unit". Click "Next".
9. Select an option to identify the Garmin unit for which you are unlocking maps. Click "Next".
10. If manually entering serial number, enter it now, click "Next", and see below for further instructions.
If connecting unit to get the Internal Unit ID number, follow prompts, and see below for further instructions.
After providing serial or Internal Unit ID number, You will be asked what product and/or region you want to unlock to this second unit. Continue to follow the prompts from there to install the code into your MapSource.