What is the name of the process that can change sedimentary or igneous rocks into metamorphic rocks?

Chemical change causes transformation of sedimentary rocks into metamorphic rocks due to high temperature and pressure.

Explanation:

If the rocks are situated deep into the earth then due to pressure and tremendous temperature of earth causes metamorphosis. The hot magma surrounds the rock and changes the shape of the rock.

Changing temperature and pressure creates unstability of the mineral constituents of the rock which is a major factor for changing the sedimentary or igneous rocks into metamorphic rocks.