It's great that you filled out the defines. But before you begin hacking away, I must warn you about something:
#define
PlayerX=[49E654]
PlayerY=[49E658]
PlayerXVel=[49E66C]
PlayerYVel=[49E670]
#enddefine
MOV EAX,PlayerXVel
Notice that PlayerX is a part of PlayerXVel.
So, that means the code will turn into this:
MOV EAX,[49E654]Vel
Because the program sees "PlayerX" and replaces it without realizing there's something on the end.
Now you have a "Vel" attached to the end of your pointer, the compiler will give you an error.
Instead, you should try to make each macro a bit more unique. So if you used PlayerXPos and PlayerYPos, this wouldn't happen.
(Actually, I'll try to fix this problem in a later update so that the defines will be mutually exclusive - the program will be able to search for the biggest strings first to avoid replacing the wrong stuff.)