Seems like I have several options, but I'm not sure which to take.

uninstall sql server from add\remove programs?

(not sure if this will release the cluster resources - eg the drives that have already been assigned to this instance)

Launch SQL Server setup - go to maintenance screen and do a remove Node?

Go into Failover Cluster Manager then click Nodes and delete the Sql server Instance then uninstall SQL Server??

so confusing!