take the Star LRT and change to Putra LRT to Bangsar station. if i not mistaken there are free shuttle(last time i hear it about ages ago) or can drop at Pasar seni and take a bus. will stop at the bustop along the Fedral Highway next to volvo(heading to Klang side)

or just get your way to KTM and get on seremban route at Sentral. Mid valley station is after KL sentral.