you could go to a salon but if you really don`t want to,
you could try a colour remover product,
but also you could try a homemade formula which would probably be better than the product..
The best I know is first getting 20-30 vitamin c tablets and crushing them,
then get a dollop of shampoo and mix them,
then add a touch of olive oil,
and massage it into your scalp,
leave it on for about 30 minutes or an hour,
or even longer,
the longer the better,
if it`s really bad,
maybe use more tablets and leave for longer!
This has worked in the past so hopefully it`ll work for you!
It should work!