You can execute package directly using dtexec.exe or through T-SQL/Stored Procedure.

Direct Execution
dtexec /F "C:\SSISSamples\Startup.dtsx"

Through T-SQL/Stored Procedure
1. Allow  your SQL Server to execute “xp_cmdshell
2. xp_cmdshell ‘dtexec /F "C:\SSISSamples\Startup.dtsx" ‘