Simple provided you have the following documents

1. 6 months bank statement
2. Old agreement (attested from labour department) which you already have for your RP stamping in passport
3. new agreement with the new position
4. passport
5. original id
6. company CR copy
7. Computer card (authorised signatory) copy
8. Baladiya copy
9. Sponsor ID copy
10. Application form
and the help of mandoop in some (most) cases
Go to labour department and once they accept it you have to go to Immigration office after 2 or 3 days and collect your new ID and new stamp in passport.