(Optional) See the Restoration Mod Steam Guide for instructions on importing your vanilla save, and checking out incompatible/included mods.
The Restoration Mod is a complete overhaul mod for Payday 2 that aims to provide a more engaging and varied experience. It completely overhauls skill trees, perk decks, weapons, enemies, enemy AI, stealth, and virtually every other aspect of gameplay. In addition, the overhaul adds a host of additional content; such as new masks, weapons, enemies, randomized time of day, and heists. Also included is the Restoration Hud- which is an optional custom hud that replicates the HUD and certain menus from alpha versions of the game.
Player progress reset: Restoration Mod's Overhaul uses a custom, separate save file to help avoid save corruption and to allow players to easily swap back to the vanilla game. Unfortunately, this means you start back at 0-0 with no money or weapons. At the bottom of the steam guide under Miscellaneous is instructions for either transferring your progress from a vanilla save, or using a feature in the mod to boost yourself to 0-100 instantly.