Cheat Engine

[Sekoia]

I've been trying to edit the damage of my weapon. I have found the part of the code that edits the value, but I don't know assembly well enough to edit it correctly.
This is the code around it (with the line in red):
add esp,10
mov [edi+000000AC],eax
test eax,eax
jle 0E0FCB7F

From what I understand, that line means "take the value in eax, and put it in the adress edi+000000AC
So by replacing eax with 0, that would mean that health is set to 0 when I hit.
However, doing that, Cheat Engine warns me that "the generated code is 10 bytes long, but the selected opcode is 6 bytes long! Do you want to replace the incomplete opcodes with NOP's?". In the past, this has always crashed it, so I don't know what to do. Any ideas?

[ParkourPenguin]

Make a code injection script.

Highlight that instruction in the disassembler, go to Tools -> Auto Assembler, and then select Template -> AOB Injection. Give a unique name to the injection (not just INJECT) and click through the other stuff. Add this instruction: