To save trim during remodeling, use two small, flat prybars. Slide the thin end of one behind the trim, pull, then insert the second in the space that opens up. Alternate pulling each bar to inch the trim off. If finishing nails protrude from the back, use slip-jaw pliers with a rounded top jaw to pull them through.
It’s possible to retrofit insulation into an existing home, even without the access provided by remodeling. The choices, however, are much more limited. There are some retrofit insulation products that are designed for minimal disruption to finished wall or ceiling surfaces. Significant gains in R-value, however, may mean hiring a professional to assess your needs and devise an energy savings plan. Small or large, insulation projects can yield substantial gains in R-value and in comfort.