What changes did the maori make to their culture arriving in NZ?

You might find some information that is helpful to you, if you read the information that is on the following sites:

New Zealand Maori Culture, Maori Culture in New Zealand (http://www.tourism.net.nz/new-zealand/about-new-zealand/maori-culture.html)

Resources on the Maori (http://www.mongabay.com/indigenous_ethnicities/pacific/Maori.html)

Fishing with New Nets: Maori Internet Information Resources and Implications of the Internet for Indigenous Peoples (http://www.isoc.org/isoc/whatis/conferences/inet/97/proceedings/E1/E1_1.HTM)