Gearbox oil change question

I am thinking if changing the gearbox oil on my car as its never been done before. I dont attempt too much mechanical work in case things go wrong!  However, read the useful guides on here and it seems straightforward apart from filling the oil which seems a bit fiddly as they mention having to remive the speedo cable to top up the last 0.50 litre.

One guide mentioned rather than do the final top up through the sppedo, to keep the car jacked up on the passenger side so the gearbox is then at an angle and you can then get the full 2 litres through the normal refill plug (providing i have checked it comes undone first!).

Has anyone done this, and if so how high do you need to jack the car up?

Just take the nearside wheel off and buy your gearbox oil in the 1 litre packs that come with the tube. The fill level is the hex plug on the side. You only need to jack the car up enough to get the wheel off and fill it through the hex plug using the litre tubed squeezy bottle. However  you may struggle to get all the oil out the litre bottles because of the angle you need to get the bottle to so maybe buy another one in case. You also need a 17mm A/F male hex to get the plugs out.
The amount the car leans with the wheel up won't make much odds to the level. It just maybe slightly over filled if you put the plug in with the wheel off but I'd rather see a little too much then not enough.

You'll never get all the oil out with the gearbox on the car so just fill it up till it runs out of the filling hole on the side of the gearbox, you can fill it with the wheels on by turning the wheels Full lock to the left then you have enough room to lye under there and see the filling hole, may not work if your car is lowered.

cheers thank you,