The peer-to-peer (P2P) architecture provides support for the next generation of information sharing applications. A difficult challenge faced by these systems in the presence of non-uniform data distribution and dynamic network conditions is load sharing. This paper addresses the problem of load sharing in P2P networks across heterogeneous super-peers. We propose two load sharing techniques that use data replication to improve access performance. In the first technique, called Periodic Push-based Replication (PPR), super-peers periodically send replicas of the most frequently accessed files to remote super-peers. This effectively reduces the hop count to fetch these files. The second technique, called On-Demand Replication (ODR), performs replication based on access frequency. By performing replication on-demand, ODR provides adaptability to changes in access behavior. Extensive testing have been conducted to study the performance of the proposed techniques. The results obtained demonstrate significant performance improvements through replication.