Mo. Rev. Stat. § 400.9-609: Secured party's right to take possession after default.

(a) After default, a secured party:

(1) May take possession of the collateral; and

(2) Without removal, may render equipment unusable and dispose of collateral on a debtor's premises under section 400.9-610.

(b) A secured party may proceed under subsection (a):

(1) Pursuant to judicial process; or

(2) Without judicial process, if it proceeds without breach of the peace.

(c) If so agreed, and in any event after default, a secured party may require the debtor to assemble the collateral and make it available to the secured party at a place to be designated by the secured party which is reasonably convenient to both parties.