Hi,
As based on personal experience, these are the requirements needed for the touristic visa:
1. arabic translation stamped on the passport
2. letter of request applied at the Libyan immigration here in Libya, reference number to be forwarded to the Libyan embassy in the place where the tourist is coming from. Upon the receipt of this ref number, it will take maximum 3 days to process the visa
3. 2-way plane ticket
These are the main requirements...