Using the Patchfiles:

There are several context diffs located in scripts/patches:
- one showing the differences between the Attachment Mod V2.3.4 to V2.3.5. (attachmod234_patch)
- one showing the differences between the Attachment Mod V2.3.5 to V2.3.6. (attachmod235_patch)
- one showing the differences between the Attachment Mod V2.3.6 to V2.3.7. (attachmod236_patch)
- one showing the differences between the Attachment Mod V2.3.7 to V2.3.8. (attachmod237_patch)
- one showing the differences between the Attachment Mod V2.3.8 to V2.3.9. (attachmod238_patch)

Ok, we are at the command line now, your phpBB2 Directory is located at board. ;)
A little example:

drwxr-xr-x    4 root     root          136 Nov  3 13:09 .
drwxr-xr-x    9 root     root          240 Nov  2 19:46 ..
drwxr-xr-x    2 root     root           48 Nov  3 13:09 OtherWebStuff
drwxr-xr-x    5 meik     users         344 Nov  2 19:50 board
-rw-r--r--    1 root     root        18500 Nov  2 19:45 attachmod238_patch

As you can see, the attachmod238_patch has to be put one instance below your phpBB2 Directory, within the example, board is the 
Directory where the phpBB2 Board is installed into.
Now we run the patch:

patch -cl -d board -p1 < attachmod238_patch

got it ?

:)
