after asking a lot of people, now I know the answer this is how it is done:Hi doorstep
Until you get an answer for your question which i am interested as well to know , i have a question related to your case, which apparently you already did.
my statement in acs says
The following employment after May 2010 is considered to equate to work at an appropriately skilled
but in EOI i added my real employment history which is may 2008.
shall i change now to May 2010 as per the assessment?
knowing that both dates will not affect my points, as i have to date same experience which is 10 years.
Basically, split that job into 2, the part that ACS took will be NOT relevant i.e. don't tick the relevant for points box. Same thing when you get the invitation, leave it as NOT Relevant for points.
may 2008 - may2010 NOT Relevant for points
April 2010 - end date Relevant for points
Since ACS took until May, you have to start from 1st of April to consider it relevant.