[bigiain]

I'd guess the same way you got your start in PHP/JS - if you're like a lot of people.

Do some personal and side projects in $newTech that you can use to show the required experience - then do the "word things carefully on your resume" thing, which emphasises both your commercial experience, and your $newTech experience, without explicitly claiming commercial experience in $newTech. Then wing it like crazy when you get an interview...