You can first try to twist it in an anticlockwise direction and then pull but if that doesnt work make a cut around the material that bonds the knob to the lever. You can then pull it out.
because vauxhauls in general has gear problems
The shift light on a Vauxhall Corsa is a light that indicates whether or not you're driving in low gear. It is typically located right on the dash.
CHAIN
chain
your corsa gearstick has gone sloppy because it needs a new gear linkage. its a common problem on corsa'a and the part is about £60 from the vauxhall dealer
yes for sure a 1.0 corsa takes about 1.6 ltr of gear box oil from emty
A vauxhall agila gear knob is hard to remove but to remove it you only need to pull it as hard as you can while twisting it then wank it will come off.
release clutch and try again
Other than a fault inside the gear-box, it's common for the linkage on top of the gear-box to wear, causing poor/difficult selection of 1st, 2nd, and sometimes reverse gear, off the top of my head the repair kit is 93181355, about £60. The repair kit is only of use as long as you can still get reverse. It's also been redesigned to reduce wear.
it has not got one you have to remove gear box sump plate
Your gear linkage would have gone, the same happened to mine, If you look under the bonnet where the gears are connected, it's like a plastic foot-long connector. If you're not sure on how to fit it, take it to your garage & you can get them to do it :)
By far the easiest way to answer this is to advise that you get the haynes manual for your model Astra. The subframe will need to be dropped to remove the gearbox.