Effectively, make the blade go down the cut line - just pull them apart and glue them on either side of the blade (and spacers).
Two points to consider - if you aren't using bolsters, cover those two holes and make sure the front of the scales are finished BEFORE you glue them on as they are nigh on impossible once they are on.
Every time I think scales are going to be dull, when I start shaping it, I get a surpise. Get filing.