Yes. Sand, clean and Kilz.

Do I have to sand to remove all of the stain or will the kilz cover. I have so much dark woodwork in my house so I would like to do it as simple as possible. Thanks so much for answering!

I'd like to see you try!! No, the sanding is merely to remove any gloss ( it may have a sealed finish) and to prep for primer adherence. A tackcloth is handy to get rid of the residue. I like to sand w a fine grade after applying the Kilz, as well.

I sand just the gloss off and then put on kilz and then sand again......is that correct. Sorry, I am not handy but really want to learn. Thanks

Post some pics of what you are trying to paint over . And you scuff sand just to remove the glossy look clean off the dust them prime then lightly sand again not removing the primer you just want it smooth then apply top coat . I would like to see the trim before you paint it