Replying to Warm wax to Cold wax

Well due to a major lack of funds I've pretty much finished my ski season here in New Zealand (gutted).
My local hill is pretty warm, so I layed on some warm conditions wax. When I got back the last time I went I caked on the warm conditions wax and didnt scrape it off...thinking I would be skiing again in the season.

But now that Im going to Tahoe for your winter (my summer) at the end of the year, Im wondering how to put the cold wax onto the skis?
Should I scrape off as much of the warm wax as possible and ski for a few days (slow skiing...)to wear it down, then put the cold wax on... or should I just scrape what I can of the warm wax off and chuck on the cold wax?

What gravity?