I have tried on several occasions, on a couple different bikes and can just not figure out how to get the top battery cover off? There appears to be a little tab down in front of it, but just no luck. I just read my service manual again and it doesnt talk about it much...
I have not had a problem with mine...just unscrew the 2 torx screws behind the battery, that hold the caddy on and then push the lid forward and manipulate to pull it off.
The battery cover on my bike (2008 RG) is very easy to remove. It also carries the engine control module, so that has to be put to the side temporarily. The ECM does not have to be unplugged.