A method of increasing a door opening width of a crossover vehicle to accommodate a wheelchair ramp or lift assembly. The method includes positioning a template on a B pillar and a template on a C pillar and marking cut lines on the pillars. The method includes cutting along the cut lines with a cutting tool to remove portions of the B pillar and the C pillar. A B pillar cover assembly is assembled and a reinforcement plate is coupled to a remaining portion of the C pillar. An adhesive is applied to the B pillar cover assembly and to a C pillar cap. A modified B pillar is produced by coupling the B pillar cover assembly to a remaining portion of the B pillar, and a modified C pillar is produced by coupling the C pillar cap to the reinforcement plate and the remaining portion of the C pillar.