Garmin updates are done via a program called Garmin Express. You can download it by Clicking Here.
Download and install the program. Connect your device to the computer and wait for the computer to recognize it. It can take anywhere from 10 seconds to 2 minutes. Once recognized, run the Garmin express program. Follow the on screen instructions to get the device added to the program. Once the device is added, select it and then Garmin express will automatically check for updates. If it finds updates, it will prompt you to install them. If you have a device with lifetime maps, then it will recognize this and prompt you to install map updates as well.
If you do not have lifetime maps, you will be taken to Garmin's website from the Garmin Express program and you will need access to your myGarmin account. If you forgot your password, you can Click Here.
In the login part on the right hand side of the screen you will see a link for forgot password. Click it and follow the instructions to get your password *****
If you have a device thats 5 years older or more, I recommend getting a sd card/micro SD card for your map updates. Maps have grown in size over the years and a lot of the older devices do not have the internal memory to hold the update.
Your 2nd option of map updates is to purchase a preloaded microSD card that has the maps on it already. You can view those by Clicking Here.
I hope this information was helpful. If you have questions about anything, please let me know.