This was done on a Lupo so it may differ slightly, I wouldn't imagine it does much. I couldn't find a pictured tutorial before replacing mines so I wrote one and decided to share it here.

Make sure you have around a couple of hours of free time, it's gonna take at least an hour.

1. Switch car off and leave it to sit for 10-15mins as it's gonna be roasting if it has been running. (I was using my car by charging batteries every night)

2. Pop the bonnet.

3. Disconnect the battery and remove it.

4. Remove the plug going into the alternator and remove the 13mm nut which I believe is the ground.

Once done move onto the bolts to remove the alternator, take the top one out first. I believe they are also 13mm iirc.

Notice the bolts hanging out.

Notice the bolt hitting the chassis leg

Drop the engine down a tad, don't jack it up as it isn't necessary. You may wish to remove one whole bolt so you have an idea of how far you can go for peace of mind. You don't have to slacken them off much, do each evenly (a turn at a time) giving the bolt a wiggle to see if it can be free'd.

These are the bolts you slacken off.

6. Once you've done that, remove the belt (just pull it to the side and then begin to lift the alternator out. It will take a bit of wiggling side to side and be careful not to bash your radiator You will then have to remove one more bolt, It is an 8mm iirc.

7. Now the alternator is ready to be taken out the car, again being careful not to bash your radiator.

8. Get your new alternator and put it in the way the old one came out do all the steps in reverse order. You will notice that the belt will be hard to put back on. What you have to do is get the belt over the new alternator and get the bottom bolt in to hold the alternator in place (the one the gets caught in the chassis leg). Once you've done that (using the same spanner that removed the alternator bolts) place the spanner on the pulley bolt and pull it right down towards you, it will get really hard to push down, whilst doing this push the alternator up into place and try and get the bolt in to hold it in place (this part is kind of a two man job). This is the most difficult part.

Once it's in place you just have the hassle of putting the plug in and the ground cable back on then tightening the engine mounts back up. Do not forget to tighten the engine mounts!!

Lastly fit your battery back in.

If you **** anything up then that's not my fault, this worked for me.

Enjoy. xx

Is Definately different on other cars.

The 13mm nut holds the LIVE feed to the alternator. It gets it's ground from being bolted to the metal engine block.

Belt is easily fitted/removed by taking the tension off with the tensioner, or winding the tension nut clockwise if on a mk1/2:3 polo. (think its clockwise anyway) (remember to slacken it off)

IMO good measure to swap the belt if history is unknown, they're around £7 usually :)

Is Definately different on other cars.

The 13mm nut holds the LIVE feed to the alternator. It gets it's ground from being bolted to the metal engine block.

Belt is easily fitted/removed by taking the tension off with the tensioner, or winding the tension nut clockwise if on a mk1/2:3 polo. (think its clockwise anyway) (remember to slacken it off)

IMO good measure to swap the belt if history is unknown, they're around £7 usually :)

I think it might be the same for a 6n and 6n2 though? Specifically a 6n2 since the Lupo and the 6n2 are pretty alike.

13mm is live feed, that clears that up.

Yeah, if you wind the tensioner nut towards you (clockwise) it slackens off so this part is the same for the mk1/2:3 as the Lupo then.

Yeah, I never replaced the belt the first time around and it was fine so I never bothered to replace it the second time - it still looked in reasonable condition and it never squeaked so never bothered to replace it :).

Nah, the later ones like a 6n/2 & Lupo etc have an auto tensioner, a mk1/2/3 you adjust it manually