The current bus schedule is leaving Narita airport T1 at 7:00 (arriving Haneda T3 at 8:40), then 7:40 (arriving 9:20). If you are checking bags, it will be very difficult to make the first bus unless your flight is early, and the second bus arrives too late to check them in at Haneda.

Without checked bags making the 7:00 bus is more likely, and the 7:40 bus will be tight but probably okay too if there's no traffic.

January is far away though, so check both the bus schedule (here) and your flight schedule to see if it changes between now and then.