You should make it if everything is on time but IME two hours is tight to change terminals at NRT. You go to a gate area, with documentation of the next flight as well as your boardiof whatever whatever from the previous flight and wait for a bus operated by your carrier. They tend to operate every half hour and are sometimes full, plus they do not operate at all during certain hours, such as mid-evening and later.

At Terminal 2, you walk a very long distance to a transfer desk which IME has only a single agent in total for all airlines. After standing in line for them to figure out how to print your boarding pass, you go through a boarding pass check, security, and then another long walk to the lounge and gate area.