Check original Play! Framework migration documentation first.
a) change Play! version from
<properties> ... <play2.version>2.1.5</play2.version> </properties>
to
<properties> ... <play2.version>2.2.6</play2.version> </properties>
b) change groupId of all Play! dependencies from play
<dependency> <groupId>play</groupId> <artifactId>play-xxxx_2.10</artifactId> <version>${play2.version}</version> </dependency>
to com.typesafe.play
<dependency> <groupId>com.typesafe.play</groupId> <artifactId>play-xxxx_2.10</artifactId> <version>${play2.version}</version> </dependency>