Trooper Billett of the Samoan Advance, 1914

Just a matter of days after New Zealand entered World War I, it was suggested by the British Government that New Zealand should send troops to occupy Western Samoa, then a German territory. By 11 August, 1413 men plus six nursing sisters had been recruited, equipped and gathered together to comprise the Samoa Advance Party, of the (3rd) Auckland regiment (Countess of Ranfurly's Own). The troops, including Private Leonard Johns Billett, travelled from Auckland to Wellington by train, and on 14th August (a public holiday) marched through Wellington streets to the Basin Reserve, past cheering crowds lining the streets. 

At the Basin Reserve, there was a final farewell from the Governor, the Earl of Liverpool, then they left Wellington on 15 August 1914 on the Monowai and the Moeraki. The journey to Samoa was uncertain in terms of safety: battleships of the German Pacific Squadron were thought to be in the area The Samoan Advance Party landed, unopposed, at Apia on 29 August 1914. 

Among the first tasks for the New Zealanders was securing the wireless station at Apia, which had been left booby-trapped by the departed German forces. Aside from that, the troops were involved during the first weeks with establish camps, digging defences, and repairing roads and bridges, as well as fortifying the wireless station.

The Samoa Relief Force took over from March 1915.

It isn't known how much longer Private Billett was in service, but if he remained with the 3rd Auckland regiment, that regiment, as part of the great Auckland Regiment, served at Gallipoli, France and Egypt.

Leonard Johns Billett died 18 March 1924, and was buried at St Ninian's Cemetery , St Georges Road, Avondale on 20 March. He was the second son of Sidney Richards Billett who, during World War I, worked as a carpenter at the Auckland Mental Hospital in Pt Chevalier. Both of L J Billett's parents, Sidney R Billett and his wife Bertha, are buried at the Billett family plot at St Ninians.

Historic images from NZETC.
Other sources: Wises Directories; Auckland Infantry, Peter Cooke, John H Gray & Ken Stead, 2010

Update, from Sandy (a comment Blogger had a snack on):

Interesting. You know me...I just can't resist....note that Leonard Johns BILLETT married 29 November 1916 at Mt Albert [Presbyterian Church] to Janet Christina Barbara NICHOLSON [1] Yet his Cenotaph Database record states his fiancee was Lizzy BROWN at the time of him enlisting in 1914. She may have died. He also has two military serial numbers, the one on the link to Cenotaph above and that which is the number on his headstone and THIS ONE 13/2531 which the record interestingly states he was born in Australia.His military records are available but currently restricted.

Cheers
Sandy

Reference:
[1]marriage registration 1916/792 Historic BDM online
https://www.bdmhistoricalrecords.dia.govt.nz/search/