We present a simulator to compare different approaches to organisation-centred MAS adaptation in a peer-to-peer (P2P) scenario. In particular, we describe our approach to MAS adaptation (2-LAMA), the P2P sharing network case study and the software we built to evaluate different alternatives. Categories and Subject Descriptors I.2.11 [Artificial Intelligence]: Distributed Artificial Intelligence--Multiagent systems, Coherence and coordination General Terms Design, Experimentation, Performance Keywords Assistance, Coordination, Organisation, P2P, MAS