retention of right

Hi, Can anyone help me to know how can I apply for non-eea nationals 'retention of right' following divorce?
is there any form?
Also do I have to or, when should I let home office know about the divorce?

I was advised from HO by phone to carry on and apply on ee4 as soon as the resident card expire, but most probably I won't be able to provide my ex-'s ID/ passport / and payslips that time (can show payslips up to the divorce).

Following is my details.

a. Got married on april 2006. my ex did not work from jan-oct 2006.

b. my ex starts to work from nov 2006 and got worker registration card on dec2006 under WRS.

c. I Applyed for FMRS in dec2006, waited 1 year, finaaly got my Resident card on jan 2008 instead of FMRS.
Got most of my ex's pay slips from nov 2006 till now (till the initiation of divorce).

d. Got proof of address from jan2006 till now.

e. Divorce process is on going, just few months before the complete 5 year is finished on nov 2011, but most probably we will be divorced way before nov.

What shall be my next move? please help--bit confused now.

Thank you