Joe and welcome from me, too.
You shouldn't have much problem swapping from a WHV to a WP as long as you have a suitable job offer. A lot of people do this.
I'm not sure that your years of work experience would be enough to cover you without having a relevant qualification. Have you checked out the
Points Indicator to see how you go. You need a minimum of 100 points to be able to apply. Finding out how many points you get would be a good place to start.
G4.1 Basic rules for work experience (26/07/99)
a. Principal applicants* must have at least 2 years' work experience to be approved in the General Skills category. Principal applicants* who do not obtain at least one point for work experience must be declined (subject to G4.1(b) below).
b. Principal applicants* are exempt from this requirement if they have completed a New Zealand qualification* (see G2.20.1) for which they have been awarded points or for which they were eligible to be awarded points but did not claim them, provided that they obtained the qualification without the assistance of NZODA funding.
c. Principal applicants* may be awarded one point for every 2 complete years' work experience, up to a maximum of 10 points.
Example: Five years of work experience would be awarded 2 points.