Process for renewing rent agreement

the process is same 

make a fresh agreement for 11 months every 11 months and no need to renew the same agreement 

if you go for more than 11 months then it should be registered 

and at first time how you made it is the same procedure right now also 

Answer to your pointwise query: 1) Same as executed for earlier agreement                                                           2)You have to called him to execution for another agreement or renewal of agreement.3) As the format is same the only thing is period is required to be changed and if amount of rent  payment is changed then it also to be changed as applicable.