Getting from Haneda Terminal 2 to Terminal 3

Hello everyone and thank you in advance.

In less than 2 week we are traveling to Japan for the first time with ANA from Heathrow to Haneda. The ticket says we land at either Terminal 2 or T3 but looking at recent previous flights they all seem to arrive at T2.

We need to get a Welcome Suica card and from what I've read they are only available from T3.

My question, how easy is it to get to T3 from T2? Also I assume that where you get the Suica card is after security?

I have also purchased a pocket WiFi, but my fault for not checking, it has to be picked up from T3.

I am hoping it is easiy enough to pop over to T3 quickly before heading to our hotel.

Thanks again!