Merge Replication: Updates to Schema

We have a main SQL Server which replicates to two backup servers via continuous merge replication. There are regular updates to the schema. Regular changes include: 1. Adding new tables and relationships with existing tables 2. Changing the data type of columns on tables already replicated **What is the easiest way to maintain replication in such an environment?** If changes are made to the publisher, some changes cannot be synced to the subscriber and the whole replication has to be setup again (agent + subscriptions). These databases are too big to replicate in its entirety every time there is an update. Any advice will be appreciated.