Once you have inserted one of the instance, you can press ctrl key and then select and drag the component into assembly.
I prefer to use the pin icon though. This is really helpful when you've mate references defined in the part and you can quickly place the component in required position (simply drag and drop).
Great, thank you. I didn't know about the ctrl + drag shortcut, that's very useful. Thanks
I actually didn't know about mate references either. That seems like a really useful tool, i'll have to look into it more. thanks for your help!