Copy both files in %appdata%/FEZ
You can rename them SaveSlot0 or SaveSlot2 as you wish. Then you can start a game from scratch while being in NG+.
Should work on any version, contact me if there's any problem. Make sure that Steam Cloud is disabled.

0% NG+

Figured it'd be good to have these made. I made practice save files for each split in the game with the current 2 8bac route. For each split with an 8bac in it, I also made a save right before the 8bac so it can be practiced specifically.

To use a save, extract it to the game's save location (see https://www.pcgamingwiki.com/wiki/Fez#Save_game_data_location for the location on your operating system) and rename it to just "SaveSlotN" where N is from 0-2, then load it in game.

Any% (Two 8BAC Route) Practice Saves

MUST RUN FILES AS ADMINISTRATOR

These are executables that will change your system clock to specific times when opened. 

File Start.bat will change your system clock to 12:00 AM, 01/01/2017.

Week Cube.bat will change your system clock to 6:00 PM, 01/02/2017.

Hour and Day cubes.bat will change your system clock to 6:15 AM, 01/02/2017.

Use file start.bat then immediately create your save file. The other files are self explanatory.

MUST RUN AS ADMINISTRATOR

Clocktower system clock changer

You will need to have a clean 1.0 GOG release of FEZ to be able to use this patch.

Note: Unstable on windows 10.

FEZ 1.07 Patch

This program is an upgrade to Juikuen's Clocktower system clock changer. Information on how to use the program is inside the zip folder.
Note: If it doesn't work try running as Administrator

FEZ System Clock Manipulation

Gyoo

Juikuen

Johnden

thearst3rd

MorganMustDie

hoto_houto

darkid

Rem_s

PlayStation 3

Xbox 360

PlayStation Vita

PlayStation 4

Android

I can´t use --gotta-gomez-fast option?

Weird glitch, room reset itself

Is Ps4 allowed on the boards? Because if not that's dumb

Saved a cycle in arch, saves 5-6 secs

True Any% - A few questions

Artefact% Routing

Wilko_314

Noice

jerrinth3glitch

Name	Manager
Clocktower system clock changer by Juikuen	Juikuen 7 years ago
FEZ System Clock Manipulation by Johnden	Johnden 6 years ago

Name	Manager
0% NG+ by Gyoo	Gyoo 10 years ago
Any% (Two 8BAC Route) Practice Saves by thearst3rd	thearst3rd 2 years ago