Old Clawfoot Tub Drain Clog

[athabasca]

I am having some drain issues with an old cast iron clawfoot tub. I cant seem to unscrew the drain, or remove the overflow plate - and honestly I just have no idea what I am doing. Here is the drain in question. There doesnt seem to be any visible screws on the overflow plate, so how do I take it off to use a plumbing snake? Or is that even what I should be doing? Any help is appreciated! Thanks!

 

[Geofd]

1st turn on the water in you bathroom sink look at the tub drain
to see if the water starts bubbling up in the tub if it does that
you snake it thru the sink

have you removed the tub strainer lots of clogs are right there
needle nose pliers work thereof you have to plunge it
use the correct plunger usually black hard rubber
and cover the over flow with a wet rag have patience

I would not recommend snaking it you could put a hole in it
there are kenetic rams that also work pump it up to 20 psi
and repeat that going up 10 psi at a time

 

[TomFOhio]

To get that overflow plate off you have to take that center knob that had the ring for the stopper and turn it out. As Geofd said be very careful because the trap is below the floor and I don't know if that tub is on first or second floor as you don't want to cause a leak