How do I exclude/rename some classes from import in Scala?

The _ has to be put at the end – not at the beginning:

Exclude Map and Set from the import

import scala.collection.mutable.{Map => _, Set => _, _}

Exclude Set and rename Map to ScalaMutableMap

import scala.collection.mutable.{Map=>ScalaMutableMap, Set => _, _}

See the detailed info in Scala Refererence, page 50, paragraph 4.7