What are the rules for deducting management fees in a 401k IRA?

There is no deduction for management fees paid inside a 401(k).  The funds in the account that are used to pay the fees are pre-tax.  Since you didn't pay tax on them, there is no deduction.  IRA fees are similar.  If you pay the fee with after tax dollars, you can claim a deduction on Schedule A (subject to some limitations).  If the fees are paid from within the IRA, they are not deductible.

Quick questions.

I have two 401K accounts from my previous employers. These two accounts are not rolled over to anywhere else and still untouched. Since I am no longer employed by either company, the management fees should be all paid for using the funds in these accounts.

Can I deduct the management fees since my previous employers are not paying them for me ? Thanks.

No, as previously stated, deductions are subtractions from taxable income. Since the dollars in a 401(k) plan were never taxed, you can't deduct the  fees  that were paid by these pre-tax dollars.