I have never done this before, but I would suggest you to do the following steps for wall prep.
1) wipe down the walls with vinegar and water solution to remove grime, grease, and stuff.
2) Lightly sand the walls not to remove the paper, but to just scuff up the surface a bit.
3) get some Zinzer B-I-N primer and put on two coats. one light coat, let it dry, then another light coat. Let both properly dry and paint in the same direction.
4) apply a very good quality latex paint. I mean paint from a retail paint store.
This should do it.
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