If you're playing with OllyDbg, you should head over to either tuts4you, exetools or woodmann forums.
You'll get plenty of information there about converting from a RVA address to a file-offset.
The other alternative, of course is to select a range of bytes starting at the target location (lets say 16) Then check to see if the bytes are unique in the memory image/exe file. If this is the case, you can just simply open, read search and replace, then write to the process's memory.
Yet another alternative is to just get an app patcher (plenty at first forum mentioned above) You give it a target exe name, a file offset or search string and finally the patch bytes. You should be able to download and configure one to 'fix' the exe file in under 20 mins.
Also, for what it's worth - if you want to change the 2 in the highlighted instruction:
MOV DWORD PTR SS:[EBP-10], 2
Then you're actually after the 4 bytes starting at the address 0x004BA5F
E
(not 0x004BA5
B
)