Looking through the VF1 Mods forum, I saw these GIMP tutorials in PDF format - apparently there was a problem with accessing the original HTML tutorials by BayouBlonde but I was able to access them here so the link must have been mended. You might however find it easier to work from the PDF version - or not as the case may be.

Because VF2 rooms are empty of furniture (apart from the bathrooms) it should be rather simpler to make changes to rooms than in VF1 as you don't have to work around the furnishings.