入境的时候，误给了B2。现在要办理学校相关手续，需要B1。学校在休斯敦，International Office的人叫去机场附近的CBP申请改为B1。给CBP打电话，叫等1小时回电话给我。现在2小时了，还没回，打过去还没人接了。有Invitation Letter 和 国内单位的过来短期访问的证明信。
请问这个转B2到B1容易吗？-Yes if the visa is B1, but the status is wrong to B2.
必须去CBP办公室才能改吗？-Yes. You can go to the local CBP Deferred Inspection Office to fix it. Find the local office in your area here (click the blue color link "Deferred Inspection Sites):
http://www.cbp.gov/xp/cgov/toolbox/contacts/deferred_inspection/
