This is the turret of my E-75 model. I've separated it from the main part as the model size was to big to upload it in a whole piece. Eventually you can easily download the rest of the model, which can be found in the list of my creations.
1). Download the "main body" part (When asked, click 'ok' on "download directly in to this model?")
2). Place it where you like.
3). Download the E-75 Turret part (Directly in to this model as well)
4). Place it near by the main body.
5). Now choose the Turret with your cursor, then select "move" tool.
6). Take the part in the marked point and place in on top of the tank, in an as well marked point.
7). You can explode the two parts if you want to make changes in it.