All patches here are the patches for source code. So you must be able to compile your own version of DOSBOX (some minimum programming knowledge is good).
I guess this is not your case, so try to find a binary. As for printer patch: it is not updated, so it would not compile with the current code anyway... But there are several older binaries in the thread which discusses it...

Mirek

Patches must be applied to the source code, which then has to be compiled by a C/C++ compiler into a new dosbox.exe. If you're not a C/C++ programmer, then you're probably best off trying to find (or asking someone to build) a custom dosbox.exe with that patch. It's possible that one already exists - there is a list of CVS builds in the development forum.