Its real easy. if you still hve the tip you can get the old bit out by heating it over a candle. typically I light the candle holding the broken side with one hand and the eyelet in the other move the steel over the flame tip while pulling the ends apart, It will come off in only a few seconds you maybe able to reuse it with a lttle sanding (not too much as it will weaken the tip).
If you take the rod to Hunting and fishing or any shop and find a tip that fits (they dont cost much)
To reattach use a hot glue gun
a little in the hole of the eyelet and a little on the rod push together quickly check alignment and you are done.
If you want you can bind the base of the eyelet any glue over(I just use my flytying bobbyn strong thread and head cement) but I dont think it is nessasary the ones I have had done in the shop never are.