First you should take you I-20,Offer letter,( TB clearance? not sure), 
Passport and so on to ISS to get an application letter for your ID. 
The ISS stuff  will tell you what you should take besides the letter 
(as far as I know, also I-20 and passport).  there's address of the 
SSN administration on the letter (you can also google it on a computer 
"SSN Administrationb Hawaii"). then you take the letter and other 
documents they ask to the ID administration, which is near the beach 
and CompUSA. You can go there by bus or by bike (about half an hour's 
ride from school) .It took me two months to get it.