What processes occur that change a sedimentary rock into an igneous rock?

It would take metamorphism,where sedimentary rock undergoes heat and pressure and turn into metamorphic rocks. The rock would then undergoes melting when it enters the mantle,it would thenturn into magma. When the magma rise up and is exposed to air due to volcanic eruption, or is cooled down below the crust it turns into igneous rock.

in short, the process would be: metamorphism>melting>solidification(lava>extrusive igneous rock)/crystallization(magma>intrusive igneous rock)

The answer is i believe low birth rights.hope my answer is the one you are looking for : )