XNB Decompiling from Steam Games?

I've been searching around for tools that'd allow me to convert xnb files to .png format in order to to access sprites from a variety of games that I own on Steam.

I've come across a few Terraria-related fragments, but none of them have been any help/have broken links/etc.

as of now, I'm looking to extract the sprite assets from Rogue Legacy, any help would be greatly appreciated!