You *can't relicense* code under your choice without the author consent

    period!
That BSD license gives permission for almost any kind of use,

including distributing the code under other licenses.  The only

requirement is not to remove the BSD license statement itself.
Another message raised the question of what relicensing means and

whether that involves changes to the code.  When I say "relicensing" I

mean distributing the code with another license applied.  That doesn't

mean deleting the old license.
The concept of relicensing does not imply changing or adding code, and

the legality of relicensing doesn't depend on changing or adding code.

However, I would urge people to relicense only if they make very big

changes.  If they make lesser changes, it is better to contribute them

to the original project, and if they make no changes, relicensing is

just silly (in most cases).