there is really no GOOD way of doing it but MOST OF THE TIME the vocal track is centered, so wat most :voice remover" plugins or apps do is remove the center pan where most of the vocals are. only works good on some songs though, and i doubt youll be able to remove the guitar, unless you find the track as seperate parts online which is highly unlikely. bands like metallica and van halen have their seperate tracks online (bass only, vocals only, instrumental) only becuase they were ripped from the guitar hero game...just gonna say.