Overview:

This DIY will explain the procedure for removing the battery on a MKII Golf, Jetta or GTI.  Note:  Before you do this job, be aware that you will lose power to the entire car.  This means that you'll lose your radio settings, the clock will go off, etc... If your radio requires a code to operate be SURE to have it ready before you remove the power.

Tools:

1) 3/8 inch drive ratchet
2) 13MM 3/8 inch drive socket
3) 15" 3/8 inch drive extension bar
4) 10MM open-ended wrench

(Pic of the tools here)

Procedure:

1)  Open the hood and locate the battery on the drivers-side of the engine bay near the front of the car.

(Img1)

2)  Using the 10MM wrench, loosten the nuts on the positive and negative terminals.

(Img2 with an arrow pointing at both bolts)

3)  Once they are both loose, pull them straight up off the battery terminals (sometimes it helps to twist) and place them behind the battery. 

(Img3 with arrows showing them being pulled off)

4)  Now we need to locate the battery hold-down clamp bolt.  It's down at the base of the front of the battery.  

(Img4 with an arrow pointing to the bolt)

5)  Using the ratchet, extension and socket, remove the bolt and clamp.  Note the orientation of the clamp so that you know how to reinstall it later!  Often times these are rusty, dirty or corroded.  Consider cleaning them up with a wire brush and painting them ot prevent further deterioration.  Also I always use anti-sieze on the threads of this bolt when reinstalling it.

(Img5)

6)  Here's the hardest part.  To remove the battery, first you need to slide it towards the front of the car slightly to disengage it from the rear clamp.  (You can't really see the clamp now, but it will become clear after the battery is out)  After you've slid it forward about 1/2 an inch, you can lift it up and slightly towards the passenger's side of the car to clear all the obstructions.  (If your MKII doesn't have power steering, it'll be alot easier for you!)  Once you've cleared everything, simply take the battery out.  Of course, be careful not to tip the battery too far from level or it may leak.  If you're keeping this battery, I suggest you wash it off with a damp cloth to remove any dirt/acid residue.  Be sure to get the bottom as well!

(Img6)

7)  You've done it!  With the battery removed you can see that rear clamp that holds on the back of the battery.  You can also see all the accumulated dirt, leaves and nastyness that seems to somehow make a home there.  :-)  

(Img7)

8)  If you want to reinstall this battery or a new one, you basically need to reverse these steps.  Be careful to put the battery back in, then slide it back about 1/2 an inch and slide it left to right a little while pushing back.  This should get you back in that rear catch.  Then reinstall the bracket and bolt.  Finally, reinstall the terminals and tighten them.

DONE!