Removing conventional wallpaper, which was applied over a properly prepared surface and with the appropriate paste is a project that, in most cases, can be accomplished in an afternoon and with little or no damage to the wallboard below.
On the other hand, removing contact paper will take more afternoons than a cat has lives and could be cause to condemn your kitchen due to the damage sustained by the wallboard when removing the contact paper.
While we are familiar with commercial solvent-containing adhesive removers we are reluctant to recommend them in this case. Our fear is that they could be absorbed into the wallboard resulting in a permanent odor that could be potentially dangerous to you and your family.
We believe that any method that you attempt to remove the contact paper will result in significant damage that will require very costly repairs. Consequently, our advice is to cover the walls in question with a new layer of 3/8" wallboard. The new layer of wallboard can be installed with drywall screws to minimize the disruption to surrounding finishes and can be finished to meet your expectations. If this task sounds like something that is more than you can handle a drywall contractor is the professional to call.