Hello to everybody, i am new on this and i have the following pins configuration on a 4 axis cnc (DB25) :

2 X step
3 X dir
4 Y step
5 Y dir
6 Z step
7 Z dir
8 A step
9 A dir
10 limit X
11 limit y
12 limit Z
13 home
14 rele out
15 E Stop
16 rele out
17 rele out

How can i do change the firmware ?
Thanks
(Sorry , i have bad english)