Downgrade from 9.2.10 to 9.2.6

All;

We have a client that rolled out several changes including an upgrade
(via the PGDG repos i.e: yum.postgresql.org) from 9.2.6 to 9.2.10

Nw we are seeing major locking issues, it comes in spikes and we see
hundreds of locks, and thousands of waiting queries when the spikes
occur. I have a hunch their issue is the in house software they
upgraded but the client thinks it's the postgres upgrade.

Question: how do we safely roll back to 9.2.6?

Can I use "yum downgrade"?
i.e.:
yum downgrade postgresql92-server-9.2.6-1PGDG.rhel6.x86_64
postgresql92-9.2.6-1PGDG.rhel6.x86_64
postgresql92-contrib-9.2.6-1PGDG.rhel6.x86_64

I assume the above approach requires the 9.2.6 packages to still be
available at yum.postgresql.org? Is this so? Is there a better method?

Thanks in advance