If you want to supplement a language after EHP Upgrade process then you can do this easily via transaction SMLT with the following steps..
Go to transaction SMLT
Select the language which you want to supplement
Go to ;
Language –> Special Actions –> Supplementation (Basic)
Fill the “Description” area , select tables for supplementation and EXECUTE
Click the YES button for the following screen
Now you can see your process as a line under the related language with Truck symbol.
Finally its completed as shown below.