?
i hope you dont mean one big hit in the middle for each fret? do you?
if so (i hope not) hit the tang farthest from you in to place, now a 1/4 of the fret is in and the rest is sticking straight inthe air (not stright up, but you get it!) now just whack it firmly in a towards you fashion, 'folding' the tang into the slot maybe 1/4" at a time; easiest thing in the world; and you can do it on a blank carved or finished neck;
even if your one of those strange people that radius and fret their boards prior to gluing , with no special cauls or nothing; just remember that you are hammering and fret end cutoffs are much stronger than wood! so keep a clean area with some support so your not chasing your neck all over!
Thanks to everyone who helped out with this, filing a pretty substantial v groove in the slot and using some thinned wood glue did the trick
Edlk