I need to write program that will change bytes in file in specific addreses. I can use only python 2.2 it's game's module so... I read once about mmap but i can't find it in python 2.2
Your best option is to manipulate the file directly; this will work regarding of Python version, i.e., 1.x, 2.x, 3.x. Here is some rough outline to get you started... if you do the actual pseudocode, it'll probably be pretty close if not exactly the correct Python:

open the file for 'r+b' (read/write; for POSIX systems, you can also just use 'r+')
go to the specific byte in question (use a file's tell() method)
write out the single byte you want changed (use a file's write() method)
close the file (use a file's close() method)
How to change byte on specific addres