Not free, but almost ($19.95) if you have to do it for business purposes:
Remove VBA Password 2.3.4 (Dombaj Soft)
Remove VBA Password instantly removes
any VBA password and unlocks locked
VBA projects in MS Excel, Word,
PowerPoint, Access, Publisher,
Outlook, FrontPage, and Project files.
Passwords of any length and character
set are supported and removed in
seconds. Intentionally or accidentally
locked VBA projects are supported.
Elian Soft Protect VBA and our VBA
Code Protector protected projects are
not supported but Excel VBA Lock
protected projects are. Features
include allowing you to view the VBA
code in PowerPoint PPA and PPAM
add-ins, removing the protection
applied with a high Office version in
a lower office version and repairing
of some VBA project damages. Supports
command-line usage (Pro edition).