Lisp - Altering dimension properties

I'm trying to write a Lisp that will change all of the dimensions
settings in an open drawing. My company used to use arrow heads
(Closed filled) for all their dimensions and would like to switch to
using Architectural tick marks.
The problem is that when we are using a drawing of something we have
created in the past, all of the dimensions have arrows and we have to
manually change all of the dimension's arrows, one by one, to arch
ticks. I know there is a way to do this in Lisp, I just haven't been
able to find it on the web. Any help would be greatly appreciated!

Thank You,
-Brian
AutoCAD 2006

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