Wintering down

I am very new to caravanning and have only had mine for about 2 months. Now is the time to tuck it  up for winter, as I very much doubt I will go away in it again until Spring (warm weather camper!! ). I've just bought my caravan cover and am going to attempt to fit it at the weekend. Does the aerial come off the roof? If not, it looks like it may point through the cover.

Can anyone give me any advice on what else I need to do? I understand that I should drain it of any water. Do I need to get a fridge vent cover?

All advice would be really appreciated as I am a complete novice.