Replaceable and Alterable

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 changed or altered in some characteristic.
  • usage: "alterable clothing"; "alterable conditions of employment"
• Of the punishment ordered by a court. ( capable of being changed to one less severe).