I have an old custom build 20lb spinng rod. Real nice but the grips are old and cracked. How do I go about putting new grips on it? It could also use a new reel seat

If the taper is not too great you can work from the butt end of the rod. After removing the old grips and reel seat use a tapered dowel to stretch a new foregrip over the butt end of the blank and slide it into place. Next install the reel seat using typcial techniques - this is where a big taper will mess things up for you, you'll wind up with an excessively large reel seat in order to fit over the butt end of the blank. Finally repeat the steps used to install the foregrip to slide on a rear grip.

I use old pool cue sticks cut to appropriate lengths so that diameters of the thick ends are slightly larger in dia than the blank you're working on so that the grip can slide off onto the blank easier. Use plenty of lube - slow curing liquid epoxy or rod finish. Warming the grips helps with the stretching.

Lou