Gen 1 Ambient temp sensor

[Parsnip]

Seems that I rhave taken a stone through the ambient temperature sensor (its tiny, talk about bad luck...) and its now reading all over the place.

Have tried a bit of googling, but it seems to throw up a lot about other temperature sensors and not the one I'm after - other than a few vague bits on a US forum.

Does anyone have any idea how to get in and replace it (bumper off job?) and a part no. - the only one I can find is an eBay jobbie...