Answer: One bit of good news is that not all authorities think voice-crossing is a bad thing. In his book, "Counterpoint," Knut Jeppeson writes, "To 'cross' the parts...is a technique which cannot be recommended sufficiently. One may say that without this no real polyphony is possible." [Footnote, p. 113, 1992 Dover Edition].

Nonetheless, the rule against voice-crossing will sometimes be enforced, and if it is being enforced in your jurisdiction then fixing it is going to require extensive rewriting of your composition. Any time two voices change places that will be considered a crossing, and you'll find that once you start revising that will require still other revisions. So it all depends on which rules you're being required to follow. Rules can be arbitrary, with their observation no more than a form of healthy exercise. But if this is an independent composition and not an exercise you might prefer to go with the advice of Jeppeson.