Yes you can change it.
Just copy the info from the old card on the computer, and then onto your new card.
With this caveat, If you are using the ext3 partition for a2sd+ on the card and your apps are there, that may be a problem.
When I have changed sd cards like this, I usually do it right before I am going to flash a new rom. That way it is a clean install, and I reload everything fresh.