hi im new to ferns

but overall well experiened with plants....but my aunt gave me a fern that had died and grew back

soooooo i need to know when she gave it to me the roots had grown out of the drainage holes and on into the ground so she pulled it up and now there roots hanging out of the pot and theres lots of dead branches in it so how do i get all the dead branches out and how do i know how much bigger to re-pot it

and what soil