for starters the model number is wrong
A "12" number would be a walk behind
Go to
www.barrettsmallengine.com/mtd/partslist/model%20and%20serial%20number.pd and download the MTD decoding files.
Then type your real model number into Partstree or jacks Small Engines web page one character at a time ( DO NOT CUT & PASTE ).
As you are typing a drop down list will appear with all the other mowers that have the same engine ,transmission & frame ( First 5 characters )
The next character is the body style and that is insignificant but will shorten the drop down list to only Yard Machines or other brands that are identical except for the colour
Changing the belts is easy but will require the use of tools, the most important one being your camera before you start.
The manual is downloadable from MTD just type in the correct model number .
It should toss up the 600 series manual which covers all of the various brands using that chassis so the photos might not be identical to your mower.
A transmission type "0" is a vari drive so you should have been supplied with 2 belts a long one & a short one, 5/8" wide but shallower than a standard B ( 5/8" ) belt.
They are L profile if that makes nay difference to you.
On your mower you have to work both from the top & the bottom so get the mower up onto stands as high as you can.
The small belt is accessed through the battery box hole and the long one from underneath.
You will also find it a lot easier if you remove the rear left wheel.
The front pulleys have to come off the engine.
I charge it out as a 2 hour job so set aside a full day.
The bit that causes the most grief is getting the front ( engine ) pulley down 2" so you can remove the belt
Do not bend the keeper tabs back out of the way because they will break off the 2nd or 3rd time you do it
When the pulley is off clean all rust up and apply some never seize.
I find it easier to leave the front pulley till last on removal & first on replacement.
