The cylinder arbor/spindle is a separate part and is threaded into the bbl assembly.
A very fine thread, no cross pin. RH thread.
They can be removed for replacement or straightening. It takes making up a tool not unlike something on the order of what is used to remove/tighten the extractor rod on the H/E cylinder assemblys.

You have to work around the top strap on the top breaks, so some thought goes into your design! but a simple but secure clamp wrench is the usual tool.
Always place a close fitting steel blank into the spindle center hole to avoid any damage to it in the clamping process.

Taking a bent one out is a little tricky as the bent stub of the spindle makes for some very abbreviated turns of the wrench tool. But once they start to turn, they come out fairly easy. a nice clean pistol like this one should be pretty easy to work on. The crusty, rusty, brown battered ones are the 'thou shall not give in' ones that defy disassembly.

With all that said,,for one that is simply bent and not worn or otherwise damaged,,the usual fix is to bend it back while it is still in the bbl assembly.
The part is soft and hasn't been seriously crimped. You'll not be bending it any more abruptly while in the bbl assembly than if you had taken it out to do the repair.
So if thoughts of it about cracking were there, it's going to happen either way. I doubt it would.

Place that close fitting slave pin back into the center hole in the spindle. Make it long enough to be able to pull it back out again when done.
You don't want a short piece dropping down in there and get stuck looking back at you.

Use a hard plastic or nylon mallet/hammer to tap the spindle back into position.
Even a hard wood block hit with a regular hammer works well (always my choice for stuff like this).
What ever you can control the best but don't damage the exterior of the spindle.

It won't take very much force at all to move it. It's a thin hollow tube is all.

You can check for centering by placing the cylinder assembly back on and the bbl back on the frame and closing, noting where they line up.

..Or you can use a simple tool they used to use for gauging.
Again a close fitting plug for the center hole of the spindle,,a slip fit with a nose turned to the dia of the locking hole in the face of the frame.
A soft coil spring is dropped into the spindle hole (ball point pen spring work good for this) and this gauge plug on top of it. The bbl closed (no cylinder assembly needed be mounted).
You very clearly see if and where the nose of that plug lands against the breech face and make some adjustments with educated mallet blows.
If you're real good,, or real lucky,,it drops right in the first time!