I don't ever recall using a vice, but yep, pair the shoes up with the springs, hold them more or less vertical and push downwards and out...although if the cam has a large diameter retainer, it can be easier to allow one shoe to sit fully home before levering the other over.
If I find them a fight, I remove the fixed and pivot pins from the brake plate.
Then fit the pins to the shoes.
That assembly is then refitted to the brake plate.
