Use RAMSession.put(IRAMSessionObject, IProgressMonitor) to commit changes to a new or updated category schema object.
//Update the Schema
newCategorySchema = session.getCategorySchema("New Category Schema");
newCategorySchema.setName("Updated Category Schema");
//Update a Category
newCategory = (RAMCategory)newCategorySchema.getCategory("New Category");
newCategory.setName("Updated Category");
//Update a Sub Category
newSubCategory = newCategory.createSubCategory("New Sub Category");
newSubCategory.setName("Updated Sub Category");
session.put(newCategorySchema, new NullProgressMonitor());