Good luck, nothing fits out of the box, you will have to drill new holes for the headlights, reshape the guards, there's a fair bit involved as I recently defacelifted a gen1
If you really want a facelift and are in auckland, I have a Legacy GT-S2 available for a reasonable price (possibly with a large discount for a swap)
If, however, you are still determined to convert your prefacelift (which are worth MUCH more) to a facelift, then I demand a firing squad.