The objective of this document is to help the Research Performing Organizations (RPOs) and Research Funding Organizations (RFOs) to develop a tailored co-design strategy and build tailored strategic change scenarios. This task is part of WP2 (Design and development of customized GEPs), which aims at developing customized Gender Equality Plans (GEPs). The purpose of the methodology guidelines is twofold: 1. Design a co-design process that will be used along the three tasks of WP2; 2. Design strategic change scenarios that will be the basis of the GEPs design. The document presents, on the one hand, theoretical insights on co-design and, on the other hand, practical steps to follow to carry out the tasks of WP2. It also provides a toolkit with practical activities that can be used in any of the tasks. These guidelines will allow for an understanding of the scope and action flow of WP2 as well as for the development of tailored strategies to develop strategic change scenarios and organize multi-stakeholder dialogues.