the sensors , as you said, have a metal clip you need to depress before it will come out of the cage.
heres a pic of one ive got lying around...
![](http://i39.photobucket.com/albums/e196/welshgar/mk4%20sensors/volksfestwales.jpg)
if youve got a very fine/small screwdriver, i found using that was easier..... the first side i took out though just came out whole....cage and all
![huh :huh:](https://www.golfgtiforum.co.uk/Smileys/modern/huh.gif.pagespeed.ce.xYYk_ElWtq.gif)
HTH a little