What is best option to approach to agree my resignation?

The following are the steps you are required to take.

1. File a resignation in accordance with the policy of the company on resignation.  If your company has no resignation policy, you have to tender your resignation at least two months before the effectivity of your resignation, in accordance with the revised Saudi Labor Law.   (At times, a company's resignation policy is implicitly included in the employment contract.  You'd better read through your contract.)

2. Get the approval of your superior for your resignation. 

3. Normally, the HR will serve you what we call as a Resignation Acceptance, along with the Schedule/Computation of your EOSB, to formalize approval of your resignation.  (To know your eligibility to receive EOSB, you may open the EOSB calculator by clicking this link, http://www.laboreducation.gov.sa/en/Con … d-Cal-5823).

You do not have to explain to your superior about your resignation.  Leaving the company for whatever reason is your right.   The company does not have the right to disapprove a resignation but has the right to extend your stay for at most three months to give them enough time to find your replacement.  Your stay can even be extended to another three months provided you agree to it. 

Each time you come back from vacation, there is no need to sign a new contract.   The first contract is enough.  As provided for in the Saudi Labor Law, your contract is deemed indefinite when your employee allows you to work after its expiration.  An indefinite contract is one that expat workers are being given.