I'm assuming the OP is aware of a basic file copy but I believe their issue is they have the packages deployed into the MSDB.
To extract packages from the MSDB, you must first identify where in the msdb they exist. For that, you can query sysssispackagefolders and sysssispackages or you can just use my query SSIS Package Query
Armed with that query, the column of interest is the PackagePath column. Couple that with dtutil and you have an extract-o-matic for package recovery.
The base form of an extract from MSDB on localhost to the current folder in the file system would look like.
dtutil /sourceserver localhost /SQL "Package" /copy file;.\Package.dtsx
Extract-o-matic
Run this query in Text mode (ctr-T) This query generates a series of dtutil calls which in turn extracts SSIS packages from a server.
;
WITH FOLDERS AS
(
-- Capture root node
SELECT
cast(PF.foldername AS varchar(max)) AS FolderPath
, PF.folderid
, PF.parentfolderid
, PF.foldername
FROM
msdb.dbo.sysssispackagefolders PF
WHERE
PF.parentfolderid IS NULL
-- build recursive hierarchy
UNION ALL
SELECT
cast(F.FolderPath + '\' + PF.foldername AS varchar(max)) AS FolderPath
, PF.folderid
, PF.parentfolderid
, PF.foldername
FROM
msdb.dbo.sysssispackagefolders PF
INNER JOIN
FOLDERS F
ON F.folderid = PF.parentfolderid
)
, PACKAGES AS
(
-- pull information about stored SSIS packages
SELECT
P.name AS PackageName
, P.id AS PackageId
, P.description as PackageDescription
, P.folderid
, P.packageFormat
, P.packageType
, P.vermajor
, P.verminor
, P.verbuild
, suser_sname(P.ownersid) AS ownername
FROM
msdb.dbo.sysssispackages P
)
SELECT
-- assumes default instance and localhost
-- use serverproperty('servername') and serverproperty('instancename')
-- if you need to really make this generic
'dtutil /sourceserver localhost /SQL "'+ F.FolderPath + '\' + P.PackageName + '" /copy file;.\' + P.PackageName +'.dtsx'
FROM
FOLDERS F
INNER JOIN
PACKAGES P
ON P.folderid = F.folderid
-- uncomment this if you want to filter out the
-- native Data Collector packages
-- WHERE
-- F.FolderPath <> '\Data Collector'