DECLARE @sql NVARCHAR(MAX);
SET @sql = N'';
SELECT  @sql = @sql + 'ALTER DATABASE ' + name + ' SET RECOVERY SIMPLE WITH NO_WAIT
GO 
'
FROM master.sys.databases
WHERE recovery_model_desc != 'simple'
-- PRINT @sql;
EXEC(@sql);

Msg 102, Level 15, State 1, Line 2
Incorrect syntax near 'GO'.

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

"It is better to light a candle than to curse the darkness."
(Chinese proverb)

DECLARE @sql nvarchar(max)
SET @sql = ''
SELECT @sql = @sql+
'DROP USER '''+name+''' 

'
FROM sys.database_principals
WHERE  principal_id > 5 AND TYPE != 'R'
--PRINT @sql
EXECUTE (@sql)

Msg 102, Level 15, State 1, Line 1
Incorrect syntax near 'UserA'.

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

DECLARE @sql nvarchar(max)
SET @sql = ''
SELECT @sql = @sql+
'DROP USER ['+name+']   --<<-- 

'
FROM sys.database_principals
WHERE  principal_id > 5 AND TYPE != 'R'
--PRINT @sql
EXECUTE (@sql)