The trim function on a full range of cells? Where/How to input?

Hello, I have a worksheet with 3,400 entries that were uploaded from an
outside program. Because the info was originally imported from our website
it contains many non printable "blank" characters at the end of all text that
I'd like to remove. If I wanted to delete all of the blank characters from
column A how do I do that? In what cell do I input the formula? and is this
the correct formula...
=TRIM(A2:A3400)? THANKS!