There's no need to do much of anything before installing the cover other than padding any sharp corners that could tear the cover. I use foam pipe wrap over the spout extensions and wrap any sharp body corners & the ends of the awning with pieces of
Reflectix, securing each piece in place with clear Duct tape which removes easily in the spring. The radio antenna I simply fold down out of the way, my Winegard TV antenna I don't bother with but if you're concerned just cover it as well with padding. I've been doing this for 10 years now with 3 different trailers, no issues at all. :B