how to convert from mybb 1.6.4 to vanilla

Hello friends,
can any one help me in converting mybb my 1.6.4 forum to vanilla.
Saw g converter but its pricy
any other alternatives

Lincoln

Only open & free option at the moment is to use the phpBB importer, then go from phpBB to Vanilla with this: http://vanillaforums.org/addon/porter-core