How can i remove bench and erpnext and reinstall

i was using a command and get following errors.:-

bench@root1-VirtualBox:~/erpnext/erpnext$ bench new-site sitename.local
MySQL root password:
Traceback (most recent call last):
File “/usr/lib/python2.7/runpy.py”, line 174, in _run_module_as_main
main”, fname, loader, pkg_name)
File “/usr/lib/python2.7/runpy.py”, line 72, in _run_code
exec code in run_globals
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/utils/bench_helper.py”, line 97, in
main()
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/utils/bench_helper.py”, line 18, in main
click.Group(commands=commands)(prog_name=‘bench’)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 764, in call
return self.main(*args, **kwargs)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 717, in main
rv = self.invoke(ctx)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 1137, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 956, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/click/core.py”, line 555, in invoke
return callback(*args, **kwargs)
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/commands/site.py”, line 33, in new_site
db_type = db_type)
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/commands/site.py”, line 66, in _new_site
source_sql=source_sql,force=force, reinstall=reinstall, db_type=db_type)
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/installer.py”, line 36, in install_db
setup_database(force, source_sql, verbose)
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/init.py”, line 16, in setup_database
return frappe.database.mariadb.setup_db.setup_database(force, source_sql, verbose)
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/mariadb/setup_db.py”, line 13, in setup_database
if force or (db_name not in dbman.get_database_list()):
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/db_manager.py”, line 58, in get_database_list
return [d[0] for d in self.db.sql(“SHOW DATABASES”)]
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/database.py”, line 120, in sql
self.connect()
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/database.py”, line 73, in connect
self._conn = self.get_connection()
File “/opt/bench/erpnext/erpnext/apps/frappe/frappe/database/mariadb/database.py”, line 85, in get_connection
local_infile = frappe.conf.local_infile)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/init.py”, line 94, in Connect
return Connection(*args, **kwargs)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/connections.py”, line 327, in init
self.connect()
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/connections.py”, line 598, in connect
self._request_authentication()
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/connections.py”, line 852, in _request_authentication
auth_packet = self._read_packet()
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/connections.py”, line 683, in _read_packet
packet.check_error()
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/protocol.py”, line 220, in check_error
err.raise_mysql_exception(self._data)
File “/opt/bench/erpnext/erpnext/env/local/lib/python2.7/site-packages/pymysql/err.py”, line 109, in raise_mysql_exception
raise errorclass(errno, errval)

Try this How do I uninstall erpnext my server? - #13 by Ahmad_Moustafa

but i also want to remove bench.

Try /home/bench - rm that?

bench remove-app erpnext

bench get-app erpnext --branch version-15