what are the necessary steps to take

Cheks, you need to apply for an M type.

Prepare the following documents in advance:
1. One completed application form (V. 2013) with a recently taken passport photo stuck on it; 2. Photocopy of your passport data page, the passport should be with at least six months of remaining validity and two blank pages; 3. Original invitation letter of duly authorized unit or confirmation letter of invitation issued by the Chinese government departments, companies and social organizations authorized by the Foreign Ministry; 4. Invitation letter issued by a trade partner in China; 5. One formal introduction letter from your company to tell your identity, the purpose of visit, and supposed duration of stay; 6. Photocopy of your company's certificate of incorporation; 7. Latest six months' bank statement of account with at least 4 million Naira in deposit if you come to China for the first time; 8. Any other documents which the Chinese consular officials view necessary.

Then submit the documents to the embassy and make an appointment for the interview.