If you don't have much more than a big suitcase on wheels, I would consider taking a train as the trains don't get stuck in traffic. (They are subject to delays but much more rarely than the bus.)

If you caught the 4:19pm NEX leaving NRT, you could connect to the Keikyu train at Shinagawa to arrive at HND at 5:55 pm. The next NEX at 4:44 pm would let you connect at Shinagawa to the Keikyu train that arrives at HND at 6:25 pm, a tight but doable check-in time by Japanese domestic flight standards.

(For domestic flights, JAL says to get through security no less than 15 minutes prior to departure, and to be at the gate no less than 10 minutes prior to departure. You can get away with such a tight lead time even at HND, although you will likely have to run from security to your gate. They will expedite you through security if you are close to the cut-off time.)