Michel,

Group the worksheets you want to change

Click on the first tab and ctrl-click on the other tabs, if you want all the
sheets right click on one and choose select all sheets.

Then do the page setup, most settings will be copied

If you already have one sheet set up like you want then with the sheet that
has the correct settings active, right-click on the sheet tab and select
"Select All Sheets", then use File/Page Setup and immediately click OK
(don't change anything). Click on some other worksheet
to get you out of "Group" mode now all sheets should have the same page
settings!

There are two EXCEPTIONS  that I can think of
Print Range
Rows to repeat at top

Cannot be copied this way