Hi I have been taking prednisone for 8 days, 60mg daily, but I got a really bad smochache and I started to vomit, can I stop it right aways or how much should I reduce the dosis and for how long

This is an incomplete question. Could you let us know why you are on Prednisolone? The stomach irritation by prednisolone is a well known fact and you can take some antacids to combat that. But predinisolone in many cases is a life saving drug and you do not want to stop it without consulting your doctor and endanger yourself.
Your doctor probably had a reason for prescribing you this and most doctors will not prescribe prednisolone unless it is absolutely necessary and only if they believe that its benefit will far outweigh the side effects.

I am taking prednisone to treat a severe neurophatic problem, but the problem is that I had an ulcer before and taking this drug is hurting my stomach. And now I am not able to eat properly because of this pain. That is why I want to stop the predinisone.

Predisone is not to be stopped abruptly, you must slowly get yourself off it, preferably with the help of your physician.

If you have not discussed this with your health care provider, I suggest you do prior to discontinuing the medication. There are other meds that can help with neuropathic disorders that do not cause GI upset.