Replaceable and Modifiable

adjective

• Capable of being replaced. .

• (a.) Capable of being replaced (by) or of being exchanged (for); as, the hydrogen of acids is replaceable by metals or by basic radicals.
• (a.) Capable or admitting of being put back into a place.
• (a.) Admitting of having its place supplied by a like thing or an equivalent; as, the lost book is replaceable.

adjective

• Capable of being modified in form or character or strength (especially by making less extreme. ) "the rhythm of physiological time is not modifiable except by interference with certain fundamental processes" - Alexis Carrel