covering letter is enough but you have to submit the copies of some past monthly returns of them and also u have to submit the newly change name proofs which ever PF official feel comfort & sufficient for them. there is no separate form for this as per my knowledge and also u can take a revised Form-2 from the name changed employees its like application form the employees.
u have a great case with u
keep update what happen at EPFO & share the EPFO experience.
1st February 2013 From India, Hyderabad