Well, you can do it by yourself to make enhance verification, you will just need to upload your documents and selfie.
If he did not it must be because he belongs to some of those countries that bittrex disabled accounts or he wants to do something obscure but can not do with his real account and for this reason he want to rent account of any other person
I wouldn't let me mom touch my account... let alone a stranger.
because they are large trades and I can't do them normally on a regular account
So verify your account, this is not something difficult to do.