(UK) Selling a Flat, anyways to lower CGT

Hiya,

Just after a little advice

Trying to sell my flat at the moment. Mortgage is at £175000 and its valued at £275000. I haven't lived there for 10 years. I have spent roughly £20000 over the years on improvements.

Anyone got any tips or tricks to lower the CGT I will have to pay?

Thanks,