Working holiday visa process in uk?

I'm currently living in china and will try and apply for the WHV while I'm back in the UK(briefly!) later this year. Can anyone tell me how long the process roughly takes? Any answers greatly appreciated!

At least three weeks, it says here.
http://www.mofa.go.jp/j_info/visit/w_holiday/programme.html#2
But as there is a limit on the number of applicants accepted, I suppose earlier the better.

I believe there is a requirement that you need to be a resident in your home country (so UK in your case) for some months consecutively before you can apply for WHV?
http://www.uk.emb-japan.go.jp/en/visa/work_hol.html

Thanks AK. Must have missed that.