I have located it now under the battery. You need to remove battery and the battery holder.

For 1.3 CDTI 2008 - with the engine and gearbox warm.

1. Remove the battery and battery tray.

2. See the gearbox filler plug on top of the gearbox, remove it.

3. Remove the drain plug from the underside of the gearbox and drain the gearbox oil.

4. Refit the drain plug (clean the plug and fit new washer if available, if not apply a little 'Hylomar' to the threads).

5. Add 2.2. litres of VX gearbox oil to the gearbox (only VX spec oil), refit the filler plug.

6. refit the battery tray and battery.

The addition of Molyslip additive can also be used to reduce whine and counter minor 2nd gear 'crunch' however some owners have reported selection issues until re-drained and re-filled without it, it worked well for me on this gearbox so I mention it here.