Notice: For this task you need to know bulgarian and macedonian. If you really thing you can do this task without knowing these two languages,  come at our IRC channel and we will see what can be done.

The bulgarian-english pair can be found this location:

https://apertium.svn.sourceforge.net/svnroot/apertium/nursery/apertium-bg-en/

The apertium-bg-en.bg-en.dix file is simply a copy of the The apertium-mk-en.mk-en.dix, 

and it needs to be translated to bulgarian from macedonian.

For this task, take the xaa file from the cgi-tasks folder (https://apertium.svn.sourceforge.net/svnroot/apertium/nursery/apertium-bg-en/cgi-tasks), and translate the source side from macedonian to bulgarian. Upload the translated file here.

Further instructions on IRC: irc.freenode.net #apertium