hex replace

[Kyme]

hi guys,

i try to make an tool to edit one file(big one, like 1,5gb)and i have to replace this 31 00 30 00 30 00 32 00 09 00 31 to this 31 00 30 00 30 00 35 00 09 00 31

i found some udf on the example forum but i don't have any ideea how to use it, it's any chance to show me someone how i can make it?

Thank you very very much

Regard's,Emanuel