Access and change models optimizer after setup

Hey,
what is the canonical way to access/change the optimizer of a pl.LightningModule after model.setup('fit') was called?

E.g. if I follow https://pytorch-lightning.readthedocs.io/en/latest/lr_finder.html (the last part where I explicitly plot the found lr and then change it) I don’t see a way how to change the optimizers lr.
If I call model.configure_optimizers() it’ll just return the optimizer and not set them.
Is there no official way to access and change them after construction?

Cheers