I didn't own my 2010 model year Cub Z-Force ZTR long enough to change oil and filters on the ZT2800's it had, but on those, the fluid drained when you removed the filters and the refill / level check plugs were on the sides (inboard, top). Just make sure you can get to and remove those refill plugs before you start. They were super tight on mine. In terms of filters, Stens has never steered me wrong. Probably nothing wrong with Chinese aftermarket ones either, it's just that you change these so rarely, I'd want a really good filter.