I wouldn't try, and odds are that it's not necessary anyway.

The whole toe-in thing is overblown anyway. In normal use the forward motion of the rim torques the brake arm rotating the shoe slightly causing the heel to dig in, and the toe to lift off. This causes higher wear at the rear, and pretty soon the shoe will wear to a toe-in pattern, such that it's flat, when turned by the moving rim.

So, you don't have to toe in shoes, since initial break in wear will do it for you soon enough.

That said, people toe in shoes because when the heel of a new shoes digs in, you get a new chalk on blackboard effect and the accompanying squeal. Toe-in became popular as a way for mechanics to satisfy complaining customers, who wouldn't accept the explanation that it would resolve by itself.

So my advice is to be patient, and appreciate the automatic horn while it lasts.

However, if the posts don't square up nicely, and the shoes are way off parallel, you might solve it by shaping the shoe to match the rim.