Hi, Welcome to LQ!
LQ has a fantastic search function that may save you time waiting for an answer to a popular question.
With over 4 million posts to search it's possible the answer has been given.
does your modem look like this one
if it is, change your search to "Huawei+E220+linux+install"
Both ubuntu and arch wikis are good sources of current information.
Check the dates, some/most forms of install/config for the modem has evolved.
What distribution of GNU/Linux are you using?
I used one for
a few years....I may be of help after you try the wikis.
hope this helps, Glenn