You could always script out the relevant tables and/or indexes by using the following statements. They create the relevant ALTER TABLE ...
or ALTER INDEX ...
statements which you can then cut & paste from the output window to the input window and use to reset the compression to NONE.
They aren't the prettiest, but they do the job.
Table objects
SELECT 'ALTER TABLE [' + ss.name + '].[' + so.name + '] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO'
/*,
so.name,
ss.name,
so.xtype,
so.uid,
so.status,
sp.data_compression_desc*/
FROM sys.partitions AS sp
JOIN sys.objects AS so
ON sp.[object_id] = so.[object_id]
JOIN sys.schemas AS ss
ON so.[schema_id] = ss.[schema_id]
WHERE 1 = 1
AND sp.data_compression_desc != N'NONE'
The ouput will look a bit like this (TEXT):
ALTER TABLE [sys].[syscsrowgroups] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER TABLE [sys].[syscscolsegments] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER TABLE [sys].[syscsdictionaries] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER TABLE [DBT].[Database] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
Index objects
SELECT 'ALTER INDEX [' + si.name + '] ON [' + ss.name + '].[' + so.name + '] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO'
/*>,
si.name,
so.name,
ss.name,
sp.data_compression_desc*/
FROM sys.indexes AS si
JOIN sys.partitions AS sp
ON si.[object_id] = sp.[object_id]
AND sp.index_id = si.index_id
JOIN sys.objects AS so
ON so.[object_id] = si.[object_id]
JOIN sys.schemas AS ss
ON so.[schema_id] = ss.[schema_id]
WHERE 1 = 1
AND sp.data_compression_desc != N'NONE'
The output will look a bit like this (TEXT):
ALTER INDEX [clust] ON [sys].[syscsrowgroups] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER INDEX [clust] ON [sys].[syscscolsegments] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER INDEX [clust] ON [sys].[syscsdictionaries] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
ALTER INDEX [CL_UX_Database_ID_DB_NAME_INST_ID] ON [DBT].[Database] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = NONE)
GO
You can build upon these scripts and add in all the relevant options for the ALTER INDEX statement.
Caution: You need enough free space in the database for the decompress to work.
Estimate size of decompressed data
With the following script you can create an output which you can then use to query all the objects that have compression turned on:
SELECT 'sp_estimate_data_compression_savings @schema_name = ''' + ss.name + ''', @object_name = ''' + so.name +
''', @index_id = ' + CAST(si.index_id AS NVARCHAR(100)) +
', @partition_number = ' + CAST(sp.partition_number AS NVARCHAR(100)) + ' , @data_compression = ''NONE''
GO'
FROM sys.indexes AS si
JOIN sys.partitions AS sp
ON si.[object_id] = sp.[object_id]
AND sp.index_id = si.index_id
JOIN sys.objects AS so
ON so.[object_id] = si.[object_id]
JOIN sys.schemas AS ss
ON so.[schema_id] = ss.[schema_id]
WHERE sp.data_compression_desc != N'NONE'
...which will generate scripts that look at bit like these examples:
sp_estimate_data_compression_savings @schema_name = 'dbo', @object_name = 'IDXProperty2', @index_id = 1, @partition_number = 1 , @data_compression = 'NONE'
GO
sp_estimate_data_compression_savings @schema_name = 'dbo', @object_name = 'IDXProperty6', @index_id = 1, @partition_number = 1 , @data_compression = 'NONE'
GO
And when you run the above statements against your database, you will get a summary of the expected decompressed data for each object. Following an example output for an object:

Good luck!