Approved H1b but want back USA on f1 and re-file H1b is it ok?

USA H1B Visa
1

Hi,

I am in situation where i have received H1b approval notification and now i want to quit the Employer “a”. what i should do to H1b transfer to employer “B” since i have just H1b Approval not the actual Visa Stamp.

  1. Before quit what documents i need to ask from my employer “a” so next H1b could get some extend benefit.
  2. Am i going to eligible for CAP-Exempt, since application has been approved.

if i am missing out something which needs to consider, please point me out

PS: I have valid F1 visa so i am going back US on f1 status again.