Unsafe Node Assassinate
On Cassandra 1.1.x, nodetool removetoken on a dead node hangs. The only way to reliably remove the node from the cluster is to use an undocumented JMX command to force the remove of the node from gossip.
Upgrading to 1.2.x and above should obviate these steps in favor of
nodetool removenode - See 1.2 Docs
It's probably also a good idea to run a
nodetool repair after this operation - See wiki