The question you ask suggests you have no clue about doing electrical repairs. Get someone COMPETENT to do it before you kill someone important - or yourself.
XXX
August 2016
It comes as a surprise to me that a kettle has a thermal fuse.
They have an ordinary 1" electrical fuse in the plug 13 Amp in the UK.
Safety regulations require appliances such as kettles and irons not to be user repairable.
You do not say the problem you have with your kettle.