When performing evolution tasks, software engineers focus on both the low-level changes required and the effects those changes will have on the system's design. The Design Snippets Tool generates partial design representations intended to help engineers address one design criterion: ease of change. In this paper, we describe a study in which participants used the Design Snippets Tool and other aids to perform a restructuring task focused on ease of change. Our findings describe how participants proceeded through the restructuring task and how they used the Design Snippets Tool. The results show that participants used the Design Snippets Tool for high-level tasks such as discovery of design problems, identification of restructuring goals, and confirmation of design improvements.