Steps 

• Go to transaction SE38 and Enter the name of the Program for which the Variant has to be transported.
• Click on "GOTO -> VARIANT".
• Click on "Utilities -> Transport Request". This will internally call a program RSTRANSP.
• Now you can see the program. Click on "Execute button"  OR Press F8.
• Choose the Variant which you want to transport, Click on "Continue" You can also choose multiple variants at a time.
• Select an existing Change Request, or Click on Create a new Change Request.
• Go to transaction SE01 and release the Change Request as you do for any other change Request

Or

You can call the program RSTRANSP and key the program and the related variants to include in a transport.

Watch this video