Q1: it really depends on the type of change. If this is a new tool we are talking about, for sure the Expectant, the Pink and the Schein theories would be the best for managing that change. What has woked best in my organization: clear, transparent and timely communication, top-down communication, open communication channels with top management, development and availability of training and support materials, change champions, gamification, as well as the involvement of all stakeholders in the change process.
Q2: Training materials and gamification are two motivators I can immediately recall, in this case, for the adoption of a new tool within the organization.