Another factor to consider is that you are withdrawing pre-tax funds and paying back the loan with after tax dollars, which will then be taxed again when it is withdrawn at retirement. While the interest rate on the loan may be low, the tax implications add to the overall costs.
Payments are generally deducted from each paycheck and must be paid in full over a maximum of 5 years. You will need to reduce your debt enough to cover these weekly, bi-monthly or monthly payments. Also, consider that any withdrawal will remove invested funds and during the payback period, this amount will no longer be growing in value to fund your retirement.