iMaps uses the auto update feature of Joomla, so you can update iMaps with only one click in the Extension Manager. iMaps is a paid extensions, so you will only be able to update the extension if you have a active subscriptions.
Step 1: Get your Download ID
Go to My downloads IDs and get your iMaps download id.
Step 2: Insert your Download ID
Go to iMaps component and click the Options button in the right corner
Add your download id
Sted 3: Update iMaps
Now go to Extension Manager >> Update and click in the button Find Updates. Select iMaps and click the Update button