Just uninstall, blizzard wont delete the account.
not entirely true!
Blizz will under some circumstances delete your account but you should be aware of the following
It is possible to request the permanent deletion of the account. However, you should be aware of the consequences:
– The in-game and forum accesses will be disabled.
– Any authentication key used on the account will be made invalid and will not be re-usable.
– You will not receive the newsletter anymore.
– The account will not be re-instated under any circumstances.
If you only wish to delete specific game licence(s) from within your Battle.net account (such as your WoW license), you’ll need to specify that in the form you’ll fill out.