You can click the top layer and then hold down Ctrl and select all the layers you want to be selected – this is a good way to do it because if there is a layer in there somewhere you don’t want selected you can bypass it by not clicking on that layer. Another way to do it is to select the top layer you want selected and go all the way to the bottom of all the layers and press Shift and while holding shift click on the bottom layer and all layers in between will be selected. If there is a layer that got selected in all that just press Ctrl and click the layer you don’t want selected and presto it’s not selected anymore but all the rest are that you wanted selected.
Once all the layers you wanted are selected put the mouse at the end of the layers and it will turn into a double pointed arrow and you can then drag them to the desired time.