You don't mention whether you are looking to sea ship or fly the bike.
The pros and cons of shipping by air vs. sea has been thoroughly discussed on the HUBB, and summarized in the following page:
In general, we suggest air shipment unless you are: 1) not in a hurry for the bike to arrive, 2) shipping TO a first world destination (Europe, North America, Australia or NZ) OR you are fluent in the local language and don't mind spending days to get your vehicle out at the destination. Keep in mind when comparing costs, that port fees in many destinations can be almost as much as the shipping cost itself! Many travellers have reported after a sea shipment that they saved almost nothing compared to an air shipment, but had a lot more grey hair at the end.
As you will note, Kathmandu doesn't fall into the definition of 1st world! As such, we would suggest air freight, and you can either go see Air New Zealand's cargo office, or if you don't mind paying for an agent to do the paperwork, any airfreight agent should be able to help you out.
If you decide to sea ship, we recommend that you deal with a major company which has their own offices at both ends, so you don't experience a runaround with an agent.
You could try Jas Jenners in Auckland, who are affiliated with Jas Worldwide. Their website has contact details:
Good luck, and let us know how you go! Don't forget to fill in the Shipping Form with your own experiences, to benefit future travellers.
"It matters not what goal you seek
Its secret here reposes:
You've got to dig from week to week
To get Results or Roses."
'One world, two wheels'