How to change the employer in my Provident fund account

how to change the employer in my pf account?

You need to download EPF transfer form from EPF India website, here is the direct link : EPF form 13.

Now submit it to HRA office of your current employer for attesting and then would be sent to HRA of your previous employer. They can even ask you to send it yourself. And once your previous employer recieves it, you should get it transferred to current employer in few days.