No need to delete the other one. Good to have both in case you want to view database from older patches. But yes, just place where your Editor is installed.
All the new schema file does is allow the RDE program to open, edit, and save the database.bin file in the format required for F1 2012 post-patch 2.
This means that you'll have to replicate any of the mods you've made to your database.bin. If you're okay with modding your database.bin (ALWAYS make a backup of the original, unmodded file ) then just open the new patch 2 database with RDE and change the variables you want - the schema xml file will allow you to do this and save in the format the recently patched F12012 needs.
If you're not up to modding your own database, then you'll have to wait for authors to update their modded db files to the patch 2 format.