Travel from Haneda Airport to Narita Airport

good day...

Please help me... my parents (both are senior citizens) will go to Canada on July 1, they will be arriving in Haneda airport ETC at 1:55 pm and their connecting flight to Canada ETC at 5:30 pm in NARITA airport... could they catch their flight going to Narita airport? what is the best way to travel going to Narita airport just to catch the flight going to Canada... please help me please...

Bus faster than train but if big traffic accident happened,,,
(No big different in day time except bad weather)
http://www.haneda-airport.jp/inter/en/access/traffic.html
http://www.limousinebus.co.jp/en/platform_searches/index/1/7
Taxi : around 27000Y (no need booking)
(include sales tax 8% and toll road fee/No need tip)

But about 3hrs transfer may not hard depends on check-in limit of NRT.
Evening NRT is very busy a lot of flights(Dom/Int'l) scheduled everyday.
http://www.narita-airport.jp/en/flight/today.html
Also don't forget HND arrival reports.
http://www.haneda-airport.jp/inter/en/flight/

Go to this page: http://www.japan-guide.com/e/e2027.html

Scroll down below the picture and the first paragraph to the box that says "To/From Tokyo Station". Click it and choose "To/From Haneda Airport". Read through the options and choose the best one for your parents.

I did domestic flight to Haneda and then international flight from Narita several times, and I strongly recommend to take limousine bus. No transfer, frequent and fast. Though they show traveling time of 80 min or so, it tend to be shorter actually.

https://www.limousinebus.co.jp/en/bus_services/narita/haneda.html

I hope your parents' flight to Haneda is domestic, since they may need additional time to go through immigration etc and the bus from international terminal is less frequent (there are free shuttle bus though).