Preferring OSPF routes over BGP

I have a branch office switch learning some routes via BGP and OSPF (same routes on both). At the moment the BGP routes come over the primary WAN connection and the OSPF over secondary WAN.

This works fine as the lower AD BGP routes are preferred and OSPF routes only become active when the BGP WAN drops.

If I needed to reverse the behavior, i.e. prefer OSPF over BGP, what would be the simplest way to do this?

I've considered sending summary routes over BGP to make them less preferred but cant as the networks are not contiguous. Would my only option be to raise the AD of the specific BGP routes (above 110) via an ACL and the distance command? I guess I would have to do that at every router that currently receives the routes in question though?

Is there a way to change how the routes are advertised at source to make them less preferred (than ospf) across all other routers?