If the hashes on the first file are in the same order as the dehashed passwords, you could just remove all the hashes by using column in notepad++ (put cursor at line 1 at the beginning of the column that includes hashes, hold down shift+alt and select all the hashes)
Then just delete/move the hashes, and use the column trick for the dehashed passwords (shift+alt select all the passes, copy them and paste them next to the first ":" on line one.