Am a Nigerian, and I want to renew my visa. How...

In general, the basic requirements for renewing a residence visa
A sponsor with a valid residence permit:
Pass the mandatory health fitness exam for those over the age of 18
Health insurance card (currently mandatory in Dubai and Abu Dhabi ONLY)
Renewal of the ID card from the Federal Authority for Identities and Nationality (ICA).
Moreover, the following documents must be attached when submitting the application:
The application form online or through a printing office licensed by the General Administration of Residency and Foreign Affairs in the competent emirate
The sponsored person's original passport
Personal photos of the sponsored person