NEWGAME 0; 400 10 15 0 0 2 200 1 0 classic 0 0 100 0 0 0 1 0 2 0 0 0 0 0 0 0.000000 0.000000 -9.820000 0 0 0
Alright so first you have to open the replay and go to the newgame line.
Then you will look for the word classic, if you are replay making in classic of course.
To the left you should see a zero, don't touch that.
Go left one more time and you will see another zero, you may change that one. I colored it red so you can see what I'm talking about.
*note: it is a one because the replay already has self damage.