How can i make a standalone patch for a executable when i know about the offset, old byte and new byte please help

See here:

http://board.flatassembler.net/topic.php?t=14320

and:

http://board.flatassembler.net/topic.php?t=14212

You can also take a look at this: http://board.flatassembler.net/topic.php?t=14143

Thanks Revolution and bzdashek

A few months late, but if some other people are looking for it, here's another one: http://board.flatassembler.net/topic.php?t=14665

k.

Without looking at the link provided above here I suppose you use the file directive and load bytes from the file directly into your data section and then write it using CreateFile api function or by using memory mapped files.