I want to change my brake fluid on my Burgman 400y (being the older model it's got the combined front and rear brake). Are there any pits falls I should be aware of? Am i correct in thinking I should start with the rear brake? I've ordered myself a brake bleeding kit, so I should be good to change it this weekend. Any advice gratefully received.

Thats correct but if its got combined brakes, do the rear first, then the combined part of the front brake, the the front brake. Just keep the fluid topped up and dont let the reservoir run dry.

Don't get any fluid on your plastics

And always use a band new sealed container of fluid.
Brake fluid absorbs water.
Once upon a time while touring in Germany I topped up fluid from someone else's old container and as I poured it in it was obvious the fluid was totally corrupted.
I then inadvertently got some of it in my mouth when I tried to siphon it back out.
Nasty.