Help with Visitor -> H1 -> F1 conversion...


Registered Users (C)
HI Folks,
I have a question on F1 stamping:
A Friend of mine has come here on Visitor\'s visa and was offered a job on H1 and after a brief time was offered Research Assistantship in a university. He has an I-20 and good academic standing with this Research based School. His passport only shows Visitor\'s visa that was valid for 3 yrs and no H1 or F1 references in the passport.
Question: What is the best way to get F1 visa stamping ? In Mexico/Canada or TTServices in India?
I really appreciate your answering this question for my friend.