Transmission Oil Level

Simple question and I await the sarcastic answers but how do you heck the oil level in the transmission?

theres a 17mm allen socket filler bung in the end near the green cap, the oil level should be just up to that

If you don't know how old the oil is change it, it's often over looked and makes a massive difference to gear changes and means the gearbox will last longer.

This is the stuff I've used, you will be luckly if you can get 2L in the gearbox after draining it out so 2 bottles is plenty.

Useful tool to undo the drain and filler plug.
http://www.ebay.co.uk/itm/DRAPER-38323-3-8-SQ-DRIVE-DRAIN-PLUG-KEY-17MM-HEX-AUDI-BMW-ROVER-VW-GEARBOX-/391539944325?hash=item5b29996b85:g:tNkAAMXQ1ZhTjJnS

Make sure you remove the filler before you undo the drain plug incase you can't get the filler off and left with no oil in the gearbox.

Thanks. Very helpful info from you both and far less sarcasm than I envisaged