Manual gearbox

Afternoon peeps. I wish to replace the gearbox oil,on my GTI. Found the drain plug.. but I can't find where you refill it. Any pointers would be great. TIA

There is a 17mm plug at the top of the Differential housing you have to either feel for it or know where it is.

Most folks including myself re-fill it from the Speedo cable hole, when removing the speedo lift both sides of the car off the ground support on Stands, then remove the 10mm bolt that holds the speedo cable in.  Car in Drive ebrake on, rotate the front tires a little left and a little right this shoudl remove the bind on the gear to allow you to get it out BE WARNED the gear can fall off the cable as you pull it and then you are looking at a whole different ball game…If it feels stuck, then rotate one of the wheels in reverse gear and try pulling it up and out..If it is binding let -her- alone and use the top fill plug.

Good vid with good view.

How to Drain Gearbox Oil | How to Refill Gear Box Oil. VW Golf. - YouTube

Where not to fill from.
VW GOLF MK1. HOW TO CHANGE GEAR /TRANSMISSION OIL, AND TOP UPS (TIPS) #golfmk1 #golfmk2 #vwfox - YouTube

https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=how-to_2%2Fguide-changing-your_6
 

I fill my gearbox with oil via the filler hole on the side of the gearbox underneath the passenger side wheel arch, turn the wheels full lock for better access. Near the green end cap, there is a plug similar to the drain plug.
On level ground and car on its wheels use a bottle with a long filler tube and squeeze the oil in till it runs out, I do lift the passenger side a little to add just a small amount more oil as I find 1 and 3/4 ish Litre will fill the gearbox.

It's not easy getting access to the speedo drive with a fuel injection engine and the plastic drive cog can fall off the cable into the gearbox which is not easy to get out. Why risk it when there is a filler hole….

http://brokevw.com/020oil.html

What oil are you going to use as upgrade to fully synthetic oil will help the cold 2nd gear crunch.  

Thank you guys for your time & knowledge. Its on axle stands at the moment.Doing other jobs ready for the MOT & the promise of better weather.

2nd what Mark says, using the speedo cable is more difficult and likely to lead to ruining your day when you pull the cable and the cog remains in the gearbox.