Advice on key problem

Hi Folks, TD5 key problem, the large unlock buuton on my key seems to have collapsed, no spring in it so nothing happens when pressed, is this easily solved, can I open it up or will it need resetting atmain stealer, have 2nd key to get on with but will need to sort this out.

Cheers all

simple spring loaded press to make contact switch - available from Maplins et al.