finding/replacing a long binary pattern in a .bin file

[yaipa]

What would be the common sense way of finding a binary pattern in a
.bin file, say some 200 bytes, and replacing it with an updated pattern
of the same length at the same offset?

Also, the pattern can occur on any byte boundary in the file, so
chunking through the code at 16 bytes a frame maybe a problem.  The
file itself isn't so large, maybe 32 kbytes is all and the need for
speed is not so great, but the need for accuracy in the
search/replacement is very important.

Thanks,

  --Alan