decoding BLOB's

Hi All;

we've found a post about dumping blobs:

I wrote:
[fanlijing wants to write bytea to file]
> A simple
>    COPY (SELECT byteacol WROM mytab WHERE ...) TO 'filename' (FORMAT
binary)
> should do the trick.

Corrections:
a) "binary" must be surrounded by single quotes.
b) that won't dump just the binary data - you would have  to remove the first 25 bytes and the last 2 bytes...

So maybe using the functions I mentioned would be the
best way after all.

You could also write your own user defined function in C.

Can someone point me in the right direction per how I would remove the first 25 bytes and the last 2 bytes from a bytea column?

Thanks in advance