Search for an asset in the asset manager. Select the asset you want to download and click the download button in the action bar.
Select one or more assets you want to download from your Asset manager. The action bar, with the download button, will pop up. Click on the download button to download all the selected assets in their original size.
You don't need the original asset in the highest resolution? Open a single asset and click 'show more' in the info panel. The single asset download button will now be visible. Click on this button and select one or more desired download presets and select the download button.
Download button grayed-out? The asset you are trying to use is restricted.