Company change

hi
i am currently work in one of the construction company in libya
but i found one job in another company. how i process the visa from another company.
i am srilankan nationality
please give on idea as soon as possible
thank you

If you're here on a residency visa, which you should be if you're working....I believe your new employer has to apply for the new visa, you'll have to leave the country, go back to your 'home country' and collect the new one.
I know 2 people from UK who've done this in the last year, they went back to London for 2 wks then came back in on their new visas.