The will outlines how his former wife had lodged a claim against him "for a further property settlement".
"The claim is misconceived and totally without merit and I direct my trustees to defend the claim... to the fullest extent possible," the will reads, according to Fairfax.
"This will include using all my estate and assets to fund such litigation if that should be necessary."
Hagaman's wife Lani was left books, paintings, wines, liquor, pets and a 1985 500SEL and 2008 GL500 Mercedes.
One of his daughters, Jennifer Lyn Elders, will receive $1.1m if she returns a hard drive from a computer owned by Hollywood Industries Ltd, a company of which Hagaman was a director until April this year.
Gold cufflinks, a diamond ring, Rolex watches and two waistcoats were left to his children.
Earl Hagaman and friend Ralph Brown bought their first hotel, the 48-room Graham Motor Inn - which is now the 130-room Scenic Hotel Franz Josef - in 1980.
Earl and Lani Hagaman started defamation proceedings against Andrew Little in June last year after the Labour leader made remarks about donations to the National Party.
Little claimed a partial victory after a jury in the High Court at Wellington in April found he had not defamed Lani Hagaman in the court case in which the Hagamans were suing for up to $2.3m.
The jury was unable to agree on whether four of the six instances claimed as defamatory by her husband, Earl Hagaman, were defamatory. In the one instance the jury decided was defamatory of Earl Hagaman, it was unable to agree whether Little could apply his defence of "qualified privilege" so could not enter a decision.
Lani Hagaman said last month that she will continue to pursue a defamation case against Little on behalf of her husband, including going ahead with a retrial.
In 2009 Earl Hagaman was awarded the inaugural New Zealand Hotel Industry Achievement Award, and in 2014 he was made a Companion of the New Zealand Order of Merit in recognition of his services to business, tourism and philanthropy.