See Browsing, searching and downloading contents from the datahub
There are 2 ways resources are stored on SmartDublin, ones where new datasets are added and those where a single dataset is updated with new information. This guide covers Adding a dataset and Updating a dataset.
Click on the Add button at the bottom of the page
You can use the handle to move the new resource to the top of the list, then use the Save Order button
then use Upload button to load current version