First step is to create a Superstar.
Go into WWE Creations and create a Superstar.
Once you are done with that simply go to Play and select your created Superstar and give yourself infinite finishers. Also select your opponent, i choose Buddy Murphy but it doesn't matter.
Advance to the next screen and go into match rules and turn on Finisher Match.
Once in the match, hit your finisher
.
After the match is over, hit rematch.
Do this 9 more times and achievement unlocked