Celements.web works mostly via so-called context menus (generally available using the right mouse button, CTRL + mouse button if you are working with an Apple Macintosh computer). Editing an element always works in accordance with the same principle:
// move the cursor into the position which you want to edit
// click the right mouse button to activated the context menu
// select the desired action (in the context menu) (with the left mouse button)
Note: Alternatively, by double clicking on the element to be edited, it is possible to switch directly to the standard editing screen of the corresponding element.